GRPU / Granite Real Estate Investment Trust - تصريحات هيئة الأوراق المالية والبورصات، التقرير السنوي، بيان الوكيل

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LEI 549300U7HUKRB4S4KZ73
CIK 1252509
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to Granite Real Estate Investment Trust
SEC Filings (Chronological Order)
توفر هذه الصفحة قائمة كاملة ومرتبة ترتيبًا زمنيًا لتصريحات هيئة الأوراق المالية والبورصات، باستثناء تصريحات الملكية التي نقدمها في مكان آخر.
January 9, 2013 15-12G

- 15-12G

15-12G 1 a13-210021512g.htm 15-12G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File Number 001-31728 GRANITE REAL ESTATE INC. (Exact

January 8, 2013 EX-99.4

GRANITE REAL ESTATE INC. GRANITE EUROPE LIMITED PARTNERSHIP GRANITE REIT HOLDINGS LIMITED PARTNERSHIP GRANITE REAL ESTATE INVESTMENT TRUST GRANITE REIT INC. BNY TRUST COMPANY OF CANADA FIRST SUPPLEMENTAL INDENTURE JANUARY 3, 2013

Exhibit 99.4 GRANITE REAL ESTATE INC. AND GRANITE EUROPE LIMITED PARTNERSHIP AND GRANITE REIT HOLDINGS LIMITED PARTNERSHIP AND GRANITE REAL ESTATE INVESTMENT TRUST AND GRANITE REIT INC. AND BNY TRUST COMPANY OF CANADA FIRST SUPPLEMENTAL INDENTURE JANUARY 3, 2013 THIS FIRST SUPPLEMENTAL INDENTURE is dated as of the 3rd day of January 2013 BETWEEN: GRANITE REAL ESTATE INC., a corporation existing un

January 8, 2013 EX-99.3

319401 Revenu Québec Certificat d'arrangement Loi sur les sociétés par actions (L.R.Q., c. S-31.1) J'atteste que la société par actions IMMOBILIER GRANITE INC. et sa ou ses versions GRANITE REAL ESTATE INC. a fait l'objet d'un arrangement approuvé pa

Exhibit 99.3 319401 Revenu Québec Certificat d'arrangement Loi sur les sociétés par actions (L.R.Q., c. S-31.1) J'atteste que la société par actions IMMOBILIER GRANITE INC. et sa ou ses versions GRANITE REAL ESTATE INC. a fait l'objet d'un arrangement approuvé par le tribunal le 3 janvier 2013 à 17 h, en vertu de la Loi sur les sociétés par actions, comme l'indiquent les statuts d'arrangement ci-j

January 8, 2013 EX-99.2

NOTICE OF CHANGE IN CORPORATE STRUCTURE PURSUANT TO SECTION 4.9 OF NATIONAL INSTRUMENT 51-102

Exhibit 99.2 NOTICE OF CHANGE IN CORPORATE STRUCTURE PURSUANT TO SECTION 4.9 OF NATIONAL INSTRUMENT 51-102 Item 1: Names of the Parties to the Transaction Granite Real Estate Inc. (“Granite Co.”), Granite Real Estate Investment Trust (“Granite REIT”), Granite REIT Inc. (“Granite GP” and, together with Granite REIT, “Granite”), Granite REIT Holdings Limited Partnership (“Granite LP”), 9268-7409 Qué

January 8, 2013 6-K

Current Report of Foreign Issuer - 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: January, 2013 Commission File Number: 001-31728 GRANITE REAL ESTATE INC.

January 8, 2013 EX-99.1

EARLY WARNING REPORT PURSUANT TO NATIONAL INSTRUMENT 62-103

Exhibit 99.1 EARLY WARNING REPORT PURSUANT TO NATIONAL INSTRUMENT 62-103 1. Name and Address of Offeror: Granite Real Estate Inc. (“Granite Co.”) Granite REIT Holdings Limited Partnership (the “Acquiror”) 77 King Street West, Suite 4010 Toronto-Dominion Centre Toronto, Ontario M5K 1H1 2. Designation and number or principal amount of securities and the Offeror’s securityholding percentage in the cl

January 7, 2013 EX-99.25

EX-99.25

NOTIFICATION OF THE REMOVAL FROM LISTING AND REGISTRATION OF THE STATED SECURITIES The New York Stock Exchange hereby notifies the SEC of its intention to remove the entire class of the stated securities from listing and registration on the Exchange at the opening of business on January 18, 2013, pursuant to the provisions of Rule 12d2-2 (a).

January 4, 2013 6-K

Current Report of Foreign Issuer - 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: January, 2013 Commission File Number: 001-31728 GRANITE REAL ESTATE INC.

January 4, 2013 EX-99.1

GRANITE COMPLETES REIT CONVERSION

Exhibit 99.1 77 King St. W., Suite 4010 P.O. Box 159 Toronto-Dominion Centre Toronto, ON, M5K 1H1 Canada GRANITE COMPLETES REIT CONVERSION January 3, 2013, Toronto, Ontario, Canada — Granite Real Estate Inc. (TSX: GRT; NYSE: GRP) (“Granite Co.”) announced today that effective January 3, 2013, it has completed its conversion from a corporate structure to a stapled unit Real Estate Investment Trust

November 20, 2012 EX-99.1

GRANITE REAL ESTATE INC. ANNOUNCES COURT APPROVAL OF PROPOSED REIT CONVERSION

EX-99.1 Exhibit 99.1 77 King St. W., Suite 4010 P.O. Box 159 Toronto-Dominion Centre Toronto, ON, M5K 1H1 Canada GRANITE REAL ESTATE INC. ANNOUNCES COURT APPROVAL OF PROPOSED REIT CONVERSION November 20, 2012, Toronto, Ontario, Canada — Granite Real Estate Inc. (TSX: GRT; NYSE: GRP) (“Granite” or the “Company”) announced today that the Superior Court of Quebec has issued a final order approving th

November 20, 2012 6-K

Current Report of Foreign Issuer - 6-K

6-K 1 d442962d6k.htm 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: November, 2012 Commission File Number: 001-31728 GRANITE REAL ESTATE INC. (Name of registrant) 77 King Street West, Suite 4010, P.O. Box 159 Toronto-Dominion Centre Toronto, Ont

November 15, 2012 EX-99.1

GRANITE SHAREHOLDERS VOTE IN FAVOUR OF PROPOSED REIT CONVERSION

EX-99.1 Exhibit 99.1 77 King St. W., Suite 4010 P.O. Box 159 Toronto-Dominion Centre Toronto, ON, M5K 1H1 Canada GRANITE SHAREHOLDERS VOTE IN FAVOUR OF PROPOSED REIT CONVERSION November 15, 2012, Toronto, Ontario, Canada — Granite Real Estate Inc. (TSX: GRT; NYSE: GRP) (“Granite” or the “Company”) is pleased to announce that its shareholders have approved the Company’s conversion to a real estate

November 15, 2012 6-K

Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: November, 2012 Commission File Number: 001-31728 GRANITE REAL ESTATE INC.

November 15, 2012 EX-99.2

GRANITE REAL ESTATE INC. Report of Voting Results for Special Meeting of Shareholders Held on November 15, 2012

EX-99.2 Exhibit 99.2 GRANITE REAL ESTATE INC. Report of Voting Results for Special Meeting of Shareholders Held on November 15, 2012 This report is being filed pursuant to section 11.3 of National Instrument 51-102 – Continuous Disclosure Obligations and discloses the voting results for each matter voted upon at the special meeting of shareholders of Granite Real Estate Inc. (the “Company”) held o

November 8, 2012 6-K

Current Report of Foreign Issuer - FORM 6-K

QuickLinks - Click here to rapidly navigate through this document UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: November, 2012 Commission File Number: 001-31728 GRANITE REAL ESTATE INC.

November 8, 2012 EX-99.1

Granite Real Estate Inc. 77 King St. W., Suite 4010 Toronto, Ontario Canada M5K 1H1 GRANITE ANNOUNCES 2012 THIRD QUARTER RESULTS

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 Third Quarter Report 2012 Granite Real Estate Inc. Granite Real Estate Inc. 77 King St. W., Suite 4010 Toronto, Ontario Canada M5K 1H1 GRANITE ANNOUNCES 2012 THIRD QUARTER RESULTS November 7, 2012, Toronto, Ontario, Canada — Granite Real Estate Inc. (TSX: GRT; NYSE: GRP) ("Granite" or the "Company") today announced its

November 8, 2012 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Michael Forsayeth, the Executive Vice-President and Chief Financial Officer of Granite Real Estate Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of Granite Real Est

November 8, 2012 EX-99.2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Thomas Heslip, the Chief Executive Officer of Granite Real Estate Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of Granite Real Estate Inc. (the "issuer") for the i

October 17, 2012 EX-99.2

Proxies submitted must be received by 10:00 am, Eastern Time, on November 13, 2012. VOTE USING THE TELEPHONE OR INTERNET 24 HOURS A DAY 7 DAYS A WEEK! • Call the number listed BELOW from a touch tone telephone. • Go to the following web site: www.inv

EX-99.2 Exhibit 99.2 GRANITE REAL ESTATE INC. Security Class Holder Account Number - Fold Form of Proxy - Special Meeting to be held on Thursday, November 15, 2012 This Form of Proxy is solicited by and on behalf of Management of the Company Notes to proxy 1. Every holder has the right to appoint some other person of their choice, who need not be a holder, to attend and act on their behalf at the

October 17, 2012 EX-99.3

Please read the accompanying Management Information Circular / Proxy Statement and the instructions attached hereto carefully before completing this Letter of Transmittal. LETTER OF TRANSMITTAL FOR REGISTERED HOLDERS OF COMMON SHARES OF GRANITE REAL

EX-99.3 Exhibit 99.3 Please read the accompanying Management Information Circular / Proxy Statement and the instructions attached hereto carefully before completing this Letter of Transmittal. LETTER OF TRANSMITTAL FOR REGISTERED HOLDERS OF COMMON SHARES OF GRANITE REAL ESTATE INC. This Letter of Transmittal is for use by registered holders (“Shareholders”) of common shares (“Granite Common Shares

October 17, 2012 6-K

Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: October, 2012 Commission File Number: 001-31728 GRANITE REAL ESTATE INC.

October 17, 2012 EX-99.5

GRANITE REAL ESTATE INC.

EX-99.5 Exhibit 99.5 GRANITE REAL ESTATE INC. CERTIFICATE I, Thomas Heslip, Chief Executive Officer of Granite Real Estate Inc. (the “Corporation”), hereby certify for and on behalf of the Corporation, and not in my personal capacity and without personal liability, that in connection with the special meeting of shareholders (the “Meeting”) of the Corporation to be held on November 15, 2012: a) the

October 17, 2012 EX-99.4

GRANITE REAL ESTATE INC. ANNOUNCES SHAREHOLDER MEETING TO APPROVE REIT CONVERSION

EX-99.4 Exhibit 99.4 77 King St. W., Suite 4010 P.O. Box 159 Toronto-Dominion Centre Toronto, ON, M5K 1H1 Canada GRANITE REAL ESTATE INC. ANNOUNCES SHAREHOLDER MEETING TO APPROVE REIT CONVERSION October 17, 2012, Toronto, Ontario, Canada — Granite Real Estate Inc. (TSX: GRT; NYSE: GRP) (“Granite” or the “Company”) is pleased to announce that on November 15, 2012 the meeting for shareholders to con

October 17, 2012 EX-99.1

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS MANAGEMENT INFORMATION CIRCULAR / PROXY STATEMENT IN RESPECT OF THE SPECIAL MEETING OF SHAREHOLDERS TO BE HELD ON THURSDAY, NOVEMBER 15, 2012 OCTOBER 11, 2012

EX-99.1 Table of Contents Exhibit 99.1 NOTICE OF SPECIAL MEETING OF SHAREHOLDERS AND MANAGEMENT INFORMATION CIRCULAR / PROXY STATEMENT IN RESPECT OF THE SPECIAL MEETING OF SHAREHOLDERS TO BE HELD ON THURSDAY, NOVEMBER 15, 2012 OCTOBER 11, 2012 Table of Contents October 11, 2012 Dear Shareholders: On behalf of our Board of Directors and management, I am pleased to invite you to a special meeting (t

September 19, 2012 6-K

Current Report of Foreign Issuer - REPORT OF FOREIGN PRIVATE ISSUER FOR THE MONTH OF SEPTEMBER 2012

OMB APPROVAL OMB Number: 3235-0116 Expires: March 31, 2014 UNITED STATES Estimated average burden hours per response 8.

September 19, 2012 EX-99.1

100 University Avenue, 9th floor

Exhibit 99.1 Exhibit 99.1 100 University Avenue, 9th floor Date: September 19, 2012 Toronto ON, M5J 2Y1 www.computershare.com To: All Canadian Securities Regulatory Authorities Subject: GRANITE REAL ESTATE INC. Dear Sirs: We advise of the following with respect to the upcoming Meeting of Security Holders for the subject Issuer: Meeting Type : Special Meeting Record Date for Notice of Meeting : 11/

August 9, 2012 6-K

Current Report of Foreign Issuer - 6-K

QuickLinks - Click here to rapidly navigate through this document UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: August, 2012 Commission File Number: 001-31728 GRANITE REAL ESTATE INC.

August 9, 2012 EX-99.2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Thomas Heslip, the Chief Executive Officer of Granite Real Estate Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of Granite Real Estate Inc. (the "issuer") for the i

August 9, 2012 EX-99.1

Granite Real Estate Inc. 77 King St. W., Suite 4010 Toronto, Ontario Canada M5K 1H1 GRANITE ANNOUNCES 2012 SECOND QUARTER RESULTS

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 Second Quarter Report 2012 Granite Real Estate Inc. Granite Real Estate Inc. 77 King St. W., Suite 4010 Toronto, Ontario Canada M5K 1H1 GRANITE ANNOUNCES 2012 SECOND QUARTER RESULTS August 8, 2012, Toronto, Ontario, Canada — Granite Real Estate Inc. (TSX: GRT; NYSE: GRP) ("Granite" or the "Company") today announced its

August 9, 2012 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Michael Forsayeth, the Executive Vice-President and Chief Financial Officer of Granite Real Estate Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of Granite Real Est

June 28, 2012 CORRESP

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CORRESP 1 filename1.htm June 28, 2012 Via E-mail and Edgar Daniel L. Gordon Branch Chief United States Securities and Exchange Commission (the “Commission”) Washington, D.C. 20549 Dear Mr. Gordon: Re: Granite Real Estate Inc. (f/k/a MI Developments Inc.) Form 40-F for the Fiscal Year Ended December 31, 2011 Filed March 13, 2012 File No. 1-31728 Thank you for your letter of June 21, 2012. We have r

June 14, 2012 6-K

Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: June, 2012 Commission File Number: 001-31728 GRANITE REAL ESTATE INC.

June 14, 2012 EX-99.1

EX-99.1

EX-99.1 Exhibit 99.1

June 14, 2012 EX-99.2

GRANITE REAL ESTATE INC. (formerly MI Developments Inc.; the “Company”) Report of Voting Results for Annual General and Special Meeting of Shareholders

EX-99.2 Exhibit 99.2 GRANITE REAL ESTATE INC. (formerly MI Developments Inc.; the “Company”) Report of Voting Results for Annual General and Special Meeting of Shareholders This report is being filed pursuant to section 11.3 of National Instrument 51-102 – Continuous Disclosure Obligations and discloses the voting results for each matter voted upon at the annual general and special meeting of shar

May 17, 2012 EX-99.1

NOTICE OF ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS MANAGEMENT INFORMATION CIRCULAR / PROXY STATEMENT IN RESPECT OF THE ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS OF MI DEVELOPMENTS INC. TO BE HELD ON JUNE 13, 2012 MAY 9, 2012

EX-99.1 Table of Contents NOTICE OF ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS AND MANAGEMENT INFORMATION CIRCULAR / PROXY STATEMENT IN RESPECT OF THE ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS OF MI DEVELOPMENTS INC. TO BE HELD ON JUNE 13, 2012 MAY 9, 2012 Table of Contents May 9, 2012 To our Shareholders: On behalf of our Board of Directors and management, I am pleased to invite

May 17, 2012 6-K

Current Report of Foreign Issuer - FORM 6-K

Form 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number: 001-31728 For the month of: May, 2012 MI DEVELOPMENTS INC.

May 17, 2012 EX-99.2

Security Class Holder Account Number Form of Proxy - Annual and Special Meeting to be held on June 13, 2012 This Form of Proxy is solicited by and on behalf of Management. Notes to proxy 1. Every holder has the right to appoint some other person of t

EX-99.2 Security Class Holder Account Number Form of Proxy - Annual and Special Meeting to be held on June 13, 2012 This Form of Proxy is solicited by and on behalf of Management. Notes to proxy 1. Every holder has the right to appoint some other person of their choice, who need not be a holder, to attend and act on their behalf at the meeting or any adjournment or postponement thereof. If you wis

May 10, 2012 EX-99.2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Thomas Heslip, the Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of MI Developments Inc. (the "issuer") for the interim p

May 10, 2012 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2012 FIRST QUARTER RESULTS

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 First Quarter Report 2012 MI Developments Inc. MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2012 FIRST QUARTER RESULTS May 9, 2012, Aurora, Ontario, Canada — MI Developments Inc. (TSX/NYSE: MIM) ("MID" or the "Company") today announced its results for the three-month peri

May 10, 2012 6-K

Current Report of Foreign Issuer - FORM 6K

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.

May 10, 2012 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Michael Forsayeth, the Executive Vice-President and Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of MI Developments Inc.

April 5, 2012 6-K

Current Report of Foreign Issuer - REPORT OF FOREIGN ISSUER FOR THE MONTH OF APRIL, 2012

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: April, 2012 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

April 5, 2012 EX-99.1

100 University Avenue, 9th floor

Exhibit 99.1 Exhibit 99.1 100 University Avenue, 9th floor Date: April 4, 2012 Toronto ON, M5J 2Y1 www.computershare.com To: All Canadian Securities Regulatory Authorities Subject: MI DEVELOPMENTS INC. Dear Sirs: We advise of the following with respect to the upcoming Meeting of Security Holders for the subject Issuer: Meeting Type : Annual Special Meeting Record Date for Notice of Meeting : 09/05

March 20, 2012 6-K

Current Report of Foreign Issuer - 6-K

6-K 1 a12-750616k.htm 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: March, 2012 Commission File Number: 001-31728 MI DEVELOPMENTS INC. (Name of registrant) 455 Magna Drive 2nd Floor Aurora, Ontario L4G 7A9 (Address of Principal Executive Office

March 20, 2012 EX-99.1

MI DEVELOPMENTS FILES YEAR END DISCLOSURE DOCUMENTS

EXHIBIT 99.1 MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9 MI DEVELOPMENTS FILES YEAR END DISCLOSURE DOCUMENTS March 19, 2012, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX/NYSE: MIM) has filed its annual report for the year ended December 31, 2011 on Form 40-F with the United States Securities and Exchange Commission. The Form 40-F, including the audited fi

March 13, 2012 EX-2

Reversal of MEC's net assets $ (84,345 ) Reclassification to income of MEC's accumulated other comprehensive income (note 12) 19,850 Reclassification to income of the noncontrolling interest in MEC (note 13) 18,322 (46,173 ) Fair value adjustment to

EX-2 3 a2206910zex-2.htm EX-2 QuickLinks - Click here to rapidly navigate through this document Exhibit 2 Audited Consolidated Financial Statements and Notes For the year ended December 31, 2011 MANAGEMENT'S RESPONSIBILITY FOR FINANCIAL REPORTING Management of MI Developments Inc. (the "Company") is responsible for the preparation and presentation of the consolidated financial statements and all t

March 13, 2012 EX-3

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QuickLinks - Click here to rapidly navigate through this document Exhibit 3 Management's Discussion and Analysis of Results of Operations and Financial Position For the three-month period and year ended December 31, 2011 Management's Discussion and Analysis of Results of Operations and Financial Position ("MD&A") of MI Developments Inc.

March 13, 2012 EX-99.1

Certification Pursuant to 18 U.S.C. 1350, As Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 MI Developments Inc.

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.1 Certification Pursuant to 18 U.S.C. 1350, As Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 MI Developments Inc. In connection with the annual report of MI Developments Inc. (the "Company") on Form 40-F for the fiscal year ended December 31, 2011 (the "Report") to which this certification is an exhibi

March 13, 2012 EX-99.2

/s/ THOMAS HESLIP Name: Thomas Heslip Title: Director and Chief Executive Officer

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.2 CERTIFICATIONS I, Thomas Heslip, certify that: 1. I have reviewed this annual report on Form 40-F of MI Developments Inc.; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances u

March 13, 2012 EX-1

MI Developments Inc. Annual Information Form March 12, 2012

Exhibit 1 MI Developments Inc. Annual Information Form March 12, 2012 TABLE OF CONTENTS Page CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS 1 CORPORATE STRUCTURE 1 GENERAL DEVELOPMENT OF THE BUSINESS 3 COMPANY OVERVIEW 6 RISK FACTORS 14 DESCRIPTION OF CAPITAL STRUCTURE 22 DIVIDEND POLICY 25 MARKET FOR SECURITIES 25 DIRECTORS AND OFFICERS 27 AUDIT COMMITTEE 33 INTEREST OF MANAGEMENT AND OTHER

March 13, 2012 EX-99.3

Certification Pursuant to 18 U.S.C. 1350, As Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 MI Developments Inc.

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.3 Certification Pursuant to 18 U.S.C. 1350, As Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 MI Developments Inc. In connection with the annual report of MI Developments Inc. (the "Company") on Form 40-F for the fiscal year ended December 31, 2011 (the "Report") to which this certification is an exhibi

March 13, 2012 EX-99.4

/s/ MICHAEL FORSAYETH Name: Michael Forsayeth Title: Chief Financial Officer

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.4 CERTIFICATIONS I, Michael Forsayeth, certify that: 1. I have reviewed this annual report on Form 40-F of MI Developments Inc.; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstanc

March 13, 2012 40-F

- FORM 40-F

QuickLinks - Click here to rapidly navigate through this document UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 40-F o REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 ý ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2011 Commission File Number 001-31728 MI DEVELOPMENTS INC.

March 13, 2012 EX-4

MI DEVELOPMENTS INC. CODE OF CONDUCT AND ETHICS As of December 7, 2011

QuickLinks - Click here to rapidly navigate through this document Exhibit 4 MI DEVELOPMENTS INC.

March 12, 2012 6-K

Current Report of Foreign Issuer - FORM 6-K

QuickLinks - Click here to rapidly navigate through this document UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of: March, 2012 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

March 12, 2012 EX-99.3

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.3 MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2011 FOURTH QUARTER AND YEAR END RESULTS March 9, 2012, Aurora, Ontario, Canada — MI Developments Inc. (TSX/NYSE: MIM) ("MID" or the "Company") today announced its results for the three-month period and year ended December 31,

March 12, 2012 EX-99.2

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QuickLinks - Click here to rapidly navigate through this document Exhibit 99.2 Management's Discussion and Analysis of Results of Operations and Financial Position For the three-month period and year ended December 31, 2011 Management's Discussion and Analysis of Results of Operations and Financial Position ("MD&A") of MI Developments Inc. ("MID" or the "Company") summarizes the significant factor

March 12, 2012 EX-99.1

Years ended December 31, 2011 2010 2009 (restated — note 20) Accounts receivable $ (3,968 ) $ (1,036 ) $ 569 Prepaid expenses and other 5,737 (5,436 ) 42 Accounts payable and accrued liabilities (9,563 ) (5,618 ) 7,350 Income taxes (5,379 ) 13,907 2,

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 Audited Consolidated Financial Statements and Notes For the year ended December 31, 2011 MANAGEMENT'S RESPONSIBILITY FOR FINANCIAL REPORTING Management of MI Developments Inc. (the "Company") is responsible for the preparation and presentation of the consolidated financial statements and all the information in the 2011

March 12, 2012 EX-99.4

(This page has been left blank intentionally.)

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.4 Annual Report 2011 MI Developments Inc. Table of Contents Letter to Shareholders 1 Management's Discussion and Analysis of Results of Operations and Financial Position 2 Management's Responsibility for Financial Reporting 44 Independent Auditors' Report of Registered Public Accounting Firm 45 Independent Auditors' Repor

February 14, 2012 SC 13G/A

GRP.U / Granite Real Estate Investment Trust / GREENLIGHT CAPITAL LLC - SCHEDULE 13G AMENDMENT - MI DEVELOPMENTS INC. Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 OMB APPROVAL OMB Number:3235-0145 Expires: February 28, 2009 Estimated average burden hours per response… 10.4 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2)* MI DEVELOPMENTS INC. (Name of Issuer) Class A Subordinate Voting Shares, no par value (Title of Class of Securities) 55304X104 (CUSIP Number) D

January 27, 2012 SC 13G/A

GRP.U / Granite Real Estate Investment Trust / FARALLON PARTNERS L L C/CA Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.

December 2, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of December 2011 Commission File Number : 001-31728 MI DEVELOPM

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of December 2011 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offi

December 2, 2011 EX-99.1

MI Developments Inc. Announces Appointment of Tom Heslip as CEO

Exhibit 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI Developments Inc. Announces Appointment of Tom Heslip as CEO December 1, 2011 — Aurora, Ontario, Canada - MI Developments Inc. (“MID”) (TSX: MIM / NYSE: MIM) announced today the appointment of Tom Heslip as Chief Executive Officer and as a Director. Mr. Heslip replaces Bill Lenehan, who had served as MID’s Interim

November 28, 2011 EX-99.1

MI Developments Inc. Announces Acceptance by TSX of Normal Course Issuer Bid

Exhibit 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI Developments Inc. Announces Acceptance by TSX of Normal Course Issuer Bid November 25, 2011 ? Aurora, Ontario, Canada - MI Developments Inc. (?MID?) (TSX: MIM / NYSE: MIM) announced today acceptance by the Toronto Stock Exchange (the ?TSX?) of MID?s Notice of intention to Make a Normal Course Issuer Bid (?NCIB?). P

November 28, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of November 2011 Commission File Number : 001-31728 MI DEVELOPM

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of November 2011 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offi

November 10, 2011 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Michael Forsayeth, the executive Vice-President and Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of MI Developments Inc.

November 10, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.

November 10, 2011 EX-99.2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

EX-99.2 3 a2206170zex-992.htm EX-99.2 QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, William Lenehan, the Interim Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of MI De

November 10, 2011 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2011 THIRD QUARTER RESULTS

QuickLinks - Click here to rapidly navigate through this document Third Quarter Report 2011 MI Developments Inc.

November 3, 2011 EX-99.1

Form 51-102F3 MATERIAL CHANGE REPORT

Exhibit 99.1 Form 51-102F3 MATERIAL CHANGE REPORT ITEM 1: REPORTING ISSUER MI Developments Inc. (?MID?) 455 Magna Drive Aurora, ON L4G 7A9 ITEM 2: DATE OF MATERIAL CHANGE October 25, 2011 ITEM 3: NEWS RELEASE On October 25, 2011, a press release (the ?Press Release?) describing the material change was issued by MID and delivered to Canada Newswire for publication and dissemination through its Cana

November 3, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of November 2011 Commission File Number : 001-31728 MI DEVELOPM

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of November 2011 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offi

November 3, 2011 EX-99.2

MI DEVELOPMENTS NOTICE OF CONFERENCE CALL FOR THIRD QUARTER 2011 RESULTS

Exhibit 99.2 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 MEDIA RELEASE MI DEVELOPMENTS NOTICE OF CONFERENCE CALL FOR THIRD QUARTER 2011 RESULTS November 2, 2011, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM, NYSE: MIM) expects to announce its financial results for the third quarter ended September 30, 2011 prior to the open of markets on Thursday, November 10,

October 26, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of October 2011 Commission File Number : 001-31728 MI DEVELOPME

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of October 2011 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offic

October 26, 2011 EX-99.1

MI Developments Inc. Announces its Strategic Plan following Completion of its Strategic Review Process

Exhibit 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario, Canada L4G 7A9 MI Developments Inc. Announces its Strategic Plan following Completion of its Strategic Review Process October 25, 2011 Aurora, Canada, MI Developments Inc. (“MID” or the “Company”) (TSX : MIM, NYSE: MIM) announced today that its Board of Directors has completed its previously announced strategic review process and u

October 11, 2011 SC 13D/A

SECURITIES AND EXCHANGE COMMISSION

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A* Amendment No. 2 (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(a) MI DEVELOPMENTS INC. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 55304X104 (CUSIP Number) Owl Creek Asset Management, L.P. 640 Fi

August 12, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.

August 12, 2011 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, John Simonetti, the Interim Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of MI Developments Inc. (the "issuer") for the

August 12, 2011 EX-99.2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, William Lenehan, the Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of MI Developments Inc. (the "issuer") for the interim

August 12, 2011 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2011 SECOND QUARTER RESULTS

QuickLinks - Click here to rapidly navigate through this document Second Quarter Report 2011 MI Developments Inc.

July 7, 2011 EX-99.1

MI DEVELOPMENTS ANNOUNCES NEW BOARD OF DIRECTORS AND NEW SENIOR MANAGEMENT TEAM

Exhibit 99.1 MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9 MI DEVELOPMENTS ANNOUNCES NEW BOARD OF DIRECTORS AND NEW SENIOR MANAGEMENT TEAM July 6, 2011, Aurora, Ontario, Canada – MI Developments Inc. (“MID”) (TSX: MIM, NYSE: MIM) announced today that following the completion on June 30, 2011 of MID’s plan of arrangement to eliminate its dual-class share structure, MID’s b

July 7, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of July 2011 Commission File Number : 001-31728 MI DEVELOPMENTS

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of July 2011 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices)

July 6, 2011 EX-99.1

Form 51-102F3 MATERIAL CHANGE REPORT

EXHIBIT 99.1 Form 51-102F3 MATERIAL CHANGE REPORT ITEM 1: REPORTING ISSUER MI Developments Inc. (“MID”) 455 Magna Drive, 2nd Floor Aurora, ON L4G 7A9 ITEM 2: DATE OF MATERIAL CHANGE June 30, 2011 ITEM 3: PRESS RELEASE On June 30, 2011, a press release (the “Press Release”) describing the material change was issued by MID and delivered to the Ontario Securities Commission and the other Canadian sec

July 6, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of July 2011 Commission File Number : 001-31728 MI DEVELOPMENTS

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of July 2011 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices)

July 1, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Final Amendment)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Final Amendment)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 55304X 10 4 (CUSIP Number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, Addre

July 1, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Final Amendment)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Final Amendment)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20 3 (CUSIP Number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, Address and Telep

July 1, 2011 EX-99.1

JOINT FILING AGREEMENT

EX-99.1 2 c19546exv99w1.htm EXHIBIT 1 EXHIBIT 1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including any and all amendments thereto) with respect to the Common Shares, no par value, of MI Developments Inc., and further agree that th

July 1, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 5)* MI Developments Inc. (Name of Issuer) Common Shares, no par value (Title of Class of Securities) (CUSIP

Schedule 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 5)* MI Developments Inc. (Name of Issuer) Common Shares, no par value (Title of Class of Securities) 55304X104 (CUSIP Number) North Run Capital, LP One International Place, Suite 2401 Boston, MA 02110 (617) 310-6130 Attention: General Counsel

June 30, 2011 EX-99.1

MI DEVELOPMENTS ELIMINATES ITS DUAL CLASS SHARE STRUCTURE

Exhibit 99.1 MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9 MI DEVELOPMENTS ELIMINATES ITS DUAL CLASS SHARE STRUCTURE June 30, 2011, Aurora, Ontario, Canada ? MI Developments Inc. (?MID?) (TSX: MIM.A, MIM.B; NYSE: MIM) announced today that the plan of arrangement to eliminate MID?s dual-class share structure has been completed and will become effective at 5:00 pm today, at

June 30, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of June 2011 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices)

June 22, 2011 SC 13G/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1) *

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.

May 12, 2011 EX-99.2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

EX-99.2 3 a2203978zex-992.htm EX-99.2 QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Frank Stronach, the Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of MI Development

May 12, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934

6-K 1 a2203978z6-k.htm 6-K QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of May 2011 Commission File Number: 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter

May 12, 2011 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

EX-99.3 4 a2203978zex-993.htm EX-99.3 QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, John Simonetti, the Interim Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of MI Dev

May 12, 2011 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2011 FIRST QUARTER RESULTS

EX-99.1 2 a2203978zex-991.htm EX-99.1 QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 First Quarter Report 2011 MI Developments Inc. MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2011 FIRST QUARTER RESULTS May 12, 2011, Aurora, Ontario, Canada — MI Developments Inc. (TSX: MIM.A, MIM.B; NYSE: MIM) ("MID" or the "Company"

May 3, 2011 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May, 2011 Commission File Number 001-31728

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May, 2011 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal exe

May 3, 2011 EX-99.1

MI DEVELOPMENTS NOTICE OF RELEASE OF FIRST QUARTER 2011 RESULTS

EX-99.1 2 a11-114331ex99d1.htm EX-99.1 EXHIBIT 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MI DEVELOPMENTS NOTICE OF RELEASE OF FIRST QUARTER 2011 RESULTS May 2, 2011, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) will announce its financial results for the first quarter ended March 31, 2011 on Thur

April 11, 2011 SC 13G/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 OMB APPROVAL OMB Number:3235-0145 Expires: February 28, 2009 Estimated average burden hours per response… 10.4 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* MI DEVELOPMENTS INC. (Name of Issuer) Class A Subordinate Voting Shares, no par value (Title of Class of Securities) 55304X104 (CUSIP Number) A

March 31, 2011 EX-99.1

COURT APPROVES REORGANIZATION PROPOSAL TO ELIMINATE MI DEVELOPMENTS’ DUAL CLASS SHARE STRUCTURE

Exhibit 99.1 MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9 COURT APPROVES REORGANIZATION PROPOSAL TO ELIMINATE MI DEVELOPMENTS? DUAL CLASS SHARE STRUCTURE March 31, 2011, Aurora, Ontario, Canada ? MI Developments Inc. (?MID?) (TSX: MIM.A, MIM.B; NYSE: MIM) announced today that the Ontario Superior Court of Justice has issued a final order approving the previously announce

March 31, 2011 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2011 Commission File Number 001-3172

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2011 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal e

March 29, 2011 EX-99.1

MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9 MI DEVELOPMENTS SHAREHOLDERS APPROVE REORGANIZATION PROPOSAL TO ELIMINATE ITS DUAL CLASS SHARE STRUCTURE

Exhibit 99.1 MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9 MI DEVELOPMENTS SHAREHOLDERS APPROVE REORGANIZATION PROPOSAL TO ELIMINATE ITS DUAL CLASS SHARE STRUCTURE March 29, 2011, Aurora, Ontario, Canada ? MI Developments Inc. ("MID") (TSX: MIM.A, MIM.B; NYSE: MIM) announced today that its shareholders have approved the previously announced reorganization proposal to elim

March 29, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2011 Commission File Number 001-31728 MI DEVELOPME

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2011 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offic

March 29, 2011 EX-99.2

MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9

Exhibit 99.2 MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9 MI DEVELOPMENTS INC. ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS Tuesday, March 29, 2011 REPORT OF VOTING RESULTS (pursuant to National Instrument 51-102 § 11.3) 1. Arrangement Resolution – the special resolution approving the plan of arrangement (the "Arrangement") under section 182 of the Business Corpora

March 11, 2011 EX-2

Years ended December 31, 2010 2009 2008 MID Restricted cash $ 801 $ — $ — Accounts receivable 30,855 571 4,954 Receivable from Reorganized MEC 41,299 — — Inventories (234 ) — — Loans receivable from MEC, net (613 ) (771 ) 17 Prepaid expenses and othe

EX-2 3 a2202515zex-2.htm EX-2 QuickLinks - Click here to rapidly navigate through this document Exhibit 2 MANAGEMENT'S RESPONSIBILITY FOR FINANCIAL REPORTING Management of MI Developments Inc. (the "Company") is responsible for the preparation and presentation of the consolidated financial statements and all the information in the 2010 Annual Report. The consolidated financial statements were prep

March 11, 2011 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2011 Commission File Number 001-3172

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2011 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal e

March 11, 2011 EX-1

MI Developments Inc. Annual Information Form March 10, 2011

Exhibit 1 MI Developments Inc. Annual Information Form March 10, 2011 TABLE OF CONTENTS Page Cautionary Note Regarding Forward-Looking Statements 1 Corporate Structure 2 Our Company 2 Proposed Reorganization 2 Corporate Structure and Subsidiaries 4 Company Overview 4 Overview 4 Our Real Estate Business 5 Our Racing and Gaming Business 9 Description of Our Real Estate Business 12 Introduction 12 De

March 11, 2011 EX-3

Management's Discussion and Analysis of Results of Operations and

EX-3 4 a2202515zex-3.htm EX-3 QuickLinks - Click here to rapidly navigate through this document Exhibit 3 Management's Discussion and Analysis of Results of Operations and Financial Position For the year ended December 31, 2010 Management's Discussion and Analysis of Results of Operations and Financial Position ("MD&A") of MI Developments Inc. ("MID" or the "Company") summarizes the significant fa

March 11, 2011 EX-1

MI DEVELOPMENTS ANNOUNCES 2010 FOURTH QUARTER AND YEAR END RESULTS

EX-1 2 a11-73847ex1.htm EX-1 EXHIBIT 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2010 FOURTH QUARTER AND YEAR END RESULTS March 10, 2011, Aurora, Ontario, Canada — MI Developments Inc. (TSX: MIM.A, MIM.B; NYSE: MIM) (“MID” or the “Company”) today announced its results for the three-month period and year ended Dec

March 11, 2011 EX-4

LETTER TO SHAREHOLDERS

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 4 LETTER TO SHAREHOLDERS Dear Shareholders: 2010 was an eventful year for MI Developments Inc.

March 11, 2011 40-F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 40-F

QuickLinks - Click here to rapidly navigate through this document UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 40-F o REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 ý ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2010 Commission File Number 001-31728 MI DEVELOPMENTS INC.

March 4, 2011 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2011 Commission File Number 001-3172

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2011 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal e

March 4, 2011 EX-99.1

MI DEVELOPMENTS NOTICE OF RELEASE OF FOURTH QUARTER AND 2010 RESULTS

EXHIBIT 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MI DEVELOPMENTS NOTICE OF RELEASE OF FOURTH QUARTER AND 2010 RESULTS Aurora, Ontario, Canada, March 3, 2011 ? MI Developments Inc. (?MID?) (TSX: MIM.A, MIM.B; NYSE: MIM) will announce its financial results for the fourth quarter and year ended December 31, 2010 on Thursday, March 10, 201

February 24, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934

6-K 1 a2202107z6-k.htm FORM 6-K QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of February 2011 Commission File Number: 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in i

February 24, 2011 EX-99.2

MR SAM SAMPLE 123 SAMPLES STREET SAMPLETOWN SS X9X 9X9 00SMIB Security Class CLASS A SUBORDINATE VOTING C1234567890 X X X Holder Account Number 9th Floor, 100 University Avenue Toronto, Ontario M5J 2Y1 www.computershare.com Fold Fold CPUQC01.E.INT/00

Exhibit 99.2 MR SAM SAMPLE 123 SAMPLES STREET SAMPLETOWN SS X9X 9X9 00SMIB Security Class CLASS A SUBORDINATE VOTING C1234567890 X X X Holder Account Number 9th Floor, 100 University Avenue Toronto, Ontario M5J 2Y1 www.computershare.com Fold Fold CPUQC01.E.INT/000001/i1234 Form of Proxy - Annual General and Special Meeting to be held on March 29, 2011 This Form of Proxy is solicited by and on beha

February 24, 2011 EX-99.1

ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS OF MI DEVELOPMENTS INC. TO BE HELD ON MARCH 29, 2011 REGARDING THE PROPOSED PLAN OF ARRANGEMENT INVOLVING MI DEVELOPMENTS INC., ITS SHAREHOLDERS AND THE OTHER PARTIES NAMED THEREIN NOTICE OF ANNUAL G

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 Neither the Canadian securities regulatory authorities nor the United States Securities and Exchange Commission nor any state securities regulatory authorities have approved or disapproved of the proposed arrangement involving MI Developments Inc. and its shareholders, or passed upon the merits or fairness of the propos

February 16, 2011 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February, 2011 Commission File Number 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February, 2011 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principa

February 16, 2011 EX-99.1

MI DEVELOPMENTS RESPONDS TO MERITLESS CORDISH COMPLAINT

Exhibit 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MI DEVELOPMENTS RESPONDS TO MERITLESS CORDISH COMPLAINT February 15, 2011, Aurora, Ontario, Canada ? MI Developments Inc. (?MID?) (TSX: MIM.A, MIM.B; NYSE: MIM) has learned via media reports that certain Cordish companies (?Cordish?) have filed a Complaint for Damages (?Complaint?) again

February 9, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 21)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20

SC 13D/A 1 dsc13da.htm AMENDMENT NO. 21 TO SCHEDULE 13D UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 21)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20 3 (CUSIP Number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 N

February 9, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 20)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 20)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 55304X 10 4 (CUSIP Number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, Addr

February 7, 2011 EX-99.1

Form 51-102F3 MATERIAL CHANGE REPORT

Exhibit 99.1 Form 51-102F3 MATERIAL CHANGE REPORT ITEM 1: REPORTING ISSUER MI Developments Inc. ("MID") 455 Magna Drive, 2nd Floor Aurora, ON L4G 7A9 ITEM 2: DATE OF MATERIAL CHANGE January 31, 2011 ITEM 3: PRESS RELEASE On January 31, 2011, a press release (the "Press Release") describing the material change was issued by MID and delivered to the Ontario Securities Commission and the other Canadi

February 7, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February, 2011 Commission File Number 001-31728 MI DEVELO

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February, 2011 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive of

February 7, 2011 EX-99.2

MI DEVELOPMENTS INC. - and - 445327 ONTARIO LIMITED - and - THE STRONACH TRUST ARRANGEMENT AGREEMENT January 31, 2011 TABLE OF CONTENTS ARTICLE 1

Exhibit 99.2 Execution Version MI DEVELOPMENTS INC. - and - 445327 ONTARIO LIMITED - and - THE STRONACH TRUST ARRANGEMENT AGREEMENT January 31, 2011 TABLE OF CONTENTS ARTICLE 1 INTERPRETATION 1.1 Definitions 2 1.2 Construction 9 1.3 Currency 10 1.4 The Trust 10 1.5 Schedules 10 ARTICLE 2 THE TRANSACTIONS 2.1 The Arrangement 10 2.2 Implementation Steps 10 2.3 Interim Order 11 2.4 Circular and Meeti

February 7, 2011 EX-99.3

AGREEMENT REGARDING ARRANGEMENT

Exhibit 99.3 AGREEMENT REGARDING ARRANGEMENT Reference is made to (a) the support agreement (the "Support Agreement") entered into among certain shareholders (each an "Initiating Shareholder", and collectively the "Initiating Shareholders") of MI Developments Inc. ("MID") and 445327 Ontario Limited ("445") between December 20, 2010 and December 22, 2010 pursuant to which such parties agreed to cau

February 3, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 12) *

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No.

February 3, 2011 SC 13D/A

SECURITIES AND EXCHANGE COMMISSION

SC 13D/A 1 p11-0245sc13da.htm MI DEVELOPMENTS INC. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A* Amendment No. 1 (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(a) MI DEVELOPMENTS INC. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 55304X104 (CU

February 3, 2011 EX-99

RELEASE

EXHIBIT 3 RELEASE Reference is hereby made to the Arrangement Agreement (the "Agreement") made the 31st day of January, 2011 by and between MI Developments Inc.

February 3, 2011 EX-99

AGREEMENT REGARDING ARRANGEMENT

EX-99 2 p11-0245exhibit2.htm EXHIBIT 2 EXHBIT 2 AGREEMENT REGARDING ARRANGEMENT Reference is made to (a) the support agreement (the "Support Agreement") entered into among certain shareholders (each an "Initiating Shareholder", and collectively the "Initiating Shareholders") of MI Developments Inc. ("MID") and 445327 Ontario Limited ("445") between December 20, 2010 and December 22, 2010 pursuant

February 3, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 20)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 20)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20 3 (CUSIP Number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, Address and Tele

February 2, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 19)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities

Schedule 13D Amendment No. 19 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 19)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 55304X 10 4 (CUSIP Number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10

February 1, 2011 EX-99.1

MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9 Tel (905) 726-7507 Fax (905) 713-6332

Exhibit 99.1 MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario L4G 7A9 Tel (905) 726-7507 Fax (905) 713-6332 MI DEVELOPMENTS ENTERS INTO AGREEMENTS FOR SHAREHOLDERS TO CONSIDER ELIMINATION OF ITS DUAL CLASS SHARE STRUCTURE January 31, 2011, Aurora, Ontario, Canada ? MI Developments Inc. ("MID") (TSX: MIM.A, MIM.B; NYSE: MIM) announced today that it has entered into definitive agreeme

February 1, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January, 2011 Commission File Number 001-31728 MI DEVELOP

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January, 2011 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive off

February 1, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 4 )* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares, no par value (Title of Class o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 4 )* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares, no par value (Title of Class of Securities) 55304X104 (CUSIP Number) North Run Capital, LP One International Place, Suite 2401 Boston, MA 02110 (617) 310-6130 Attention: General Co

February 1, 2011 SC 13G

OMB APPROVAL

Schedule 13G OMB APPROVAL OMB Number: 3235-0145 Expires: February 28, 2009 Estimated average burden hours per response .

February 1, 2011 EX-99.3

AGREEMENT REGARDING ARRANGEMENT

EX-99.3 3 c11725exv99w3.htm EXHIBIT 3 Exhibit 3 AGREEMENT REGARDING ARRANGEMENT Reference is made to (a) the support agreement (the “Support Agreement”) entered into among certain shareholders (each an “Initiating Shareholder”, and collectively the “Initiating Shareholders”) of MI Developments Inc. (“MID”) and 445327 Ontario Limited (“445”) between December 20, 2010 and December 22, 2010 pursuant

February 1, 2011 EX-99.1

JOINT FILING AGREEMENT

Exhibit 1 EXHIBIT 1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including any and all amendments thereto) with respect to the to Class A Subordinate Voting Shares, no par value, of MI Developments Inc.

January 11, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 11) *

SC 13D/A 1 mid13da.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 11) * MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 55304X104 (Cusip Number) Mark C. Wehrly Farallon Capital Management, L.L.C. One Maritime Plaza, Suite 2100 San Francisco, Califo

January 5, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 18)* MI Developments Inc. (Name of issuer) Class A Subordinate Voting Shares (Title of class of securities

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 18)* MI Developments Inc. (Name of issuer) Class A Subordinate Voting Shares (Title of class of securities) 55304X 10 4 (CUSIP number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, addr

January 5, 2011 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 19)* MI Developments Inc. (Name of issuer) Class B Subordinate Voting Shares (Title of class of securities

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 19)* MI Developments Inc. (Name of issuer) Class B Subordinate Voting Shares (Title of class of securities) 55304X 20 3 (CUSIP number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, addr

January 3, 2011 EX-99.1

Form 51-102F3 MATERIAL CHANGE REPORT

Exhibit 99.1 Form 51-102F3 MATERIAL CHANGE REPORT ITEM 1: REPORTING ISSUER MI Developments Inc. (?MID?) 455 Magna Drive, 2nd Floor Aurora, ON L4G 7A9 ITEM 2: DATE OF MATERIAL CHANGE December 22, 2010 ITEM 3: PRESS RELEASE On December 22, 2010, a press release (the ?Press Release?) describing the material change was issued by MID and delivered to the Ontario Securities Commission and the other Cana

January 3, 2011 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of January 2011 Commission File Number : 001-31728 MI DEVELOPME

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of January 2011 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offic

December 30, 2010 SC 13D

SECURITIES AND EXCHANGE COMMISSION

SC 13D 1 p10-2047sc13d.htm MI DEVELOPMENTS INC. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(a) Under the Securities Exchange Act of 1934 (Amendment No. )* MI DEVELOPMENTS INC. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Se

December 23, 2010 EX-2

SUPPORT AGREEMENT

EX-2 3 c10226exv2.htm EXHIBIT 2 EXHIBIT 2 SUPPORT AGREEMENT FOR GOOD AND VALUABLE CONSIDERATION, the receipt and sufficiency of which are acknowledged, the shareholders (each a “Shareholder”, and collectively the “Initiating Shareholders”) of MI Developments Inc. (the “Company”) listed in the attached Schedule A, and such other direct or indirect shareholders of the Company who may execute a count

December 23, 2010 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 10) * MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 5

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No.

December 23, 2010 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 3 )* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares, no par value (Title of Class o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 3 )* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares, no par value (Title of Class of Securities) 55304X104 (CUSIP Number) North Run Capital, LP One International Place, Suite 2401 Boston, MA 02110 (617) 310-6130 Attention: General Co

December 23, 2010 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 17)* MI Developments Inc. (Name of issuer) Class A Subordinate Voting Shares (Title of class of securities

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 17)* MI Developments Inc. (Name of issuer) Class A Subordinate Voting Shares (Title of class of securities) 55304X 10 4 (CUSIP number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, addr

December 23, 2010 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 18)* MI Developments Inc. (Name of issuer) Class B Voting Shares (Title of class of securities) 55304X 20

Schedule 13D Amendment No. 18 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 18)* MI Developments Inc. (Name of issuer) Class B Voting Shares (Title of class of securities) 55304X 20 3 (CUSIP number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 88

December 23, 2010 EX-1

JOINT FILING AGREEMENT

EX-1 2 c10226exv1.htm EXHIBIT 1 EXHIBIT 1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including any and all amendments thereto) with respect to the to Class A Subordinate Voting Shares, no par value, of MI Developments Inc., and furt

December 22, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of December 2010 Commission File Number : 001-31728 MI DEVELOPM

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of December 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offi

December 22, 2010 EX-99.1

MI DEVELOPMENTS RECEIVES PROPOSAL FOR ELIMINATION OF DUAL CLASS SHARE STRUCTURE FROM CLASS A SHAREHOLDERS AND ITS CONTROLLING SHAREHOLDER

EXHIBIT 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MI DEVELOPMENTS RECEIVES PROPOSAL FOR ELIMINATION OF DUAL CLASS SHARE STRUCTURE FROM CLASS A SHAREHOLDERS AND ITS CONTROLLING SHAREHOLDER December 22, 2010, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) announced that its Board of Directors has rec

December 14, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of December 2010 Commission File Number: 001-31728 MI DEVELOPME

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.

December 14, 2010 EX-99.2

FORM 52-109F2R CERTIFICATION OF REFILED INTERIM FILINGS

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.2 FORM 52-109F2R CERTIFICATION OF REFILED INTERIM FILINGS This certificate is being filed on the same date that MI Developments Inc. (the "issuer") has refiled its interim financial statements and interim MD&A for the interim period ended September 30, 2010. I, Frank Stronach, the Chief Executive Officer of MI Development

December 14, 2010 EX-99.3

FORM 52-109F2R CERTIFICATION OF REFILED INTERIM FILINGS

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.3 FORM 52-109F2R CERTIFICATION OF REFILED INTERIM FILINGS This certificate is being filed on the same date that MI Developments Inc. (the "issuer") has refiled its interim financial statements and interim MD&A for the interim period ended September 30, 2010. I, Rocco Liscio, the Executive Vice-President and Chief Executiv

December 14, 2010 EX-99.1

Average Exchange Rates Three Months Ended September 30, Average Exchange Rates Nine Months Ended September 30, 2010 2009 Change 2010 2009 Change 1 Canadian dollar equals U.S. dollars 0.962 0.914 5% 0.966 0.858 13% 1 euro equals U.S. dollars 1.293 1.4

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 Third Quarter Report (Amended and Restated) 2010 MI Developments Inc. Amended and Restated Management's Discussion and Analysis of Results of Operations and Financial Position For the three and nine-month periods ended September 30, 2010 Management's Discussion and Analysis of Results of Operations and Financial Positio

December 14, 2010 EX-99.4

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.4 MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2010 RESTATED THIRD QUARTER RESULTS December 14, 2010, Aurora, Ontario, Canada — MI Developments Inc. (TSX: MIM.A, MIM.B; NYSE: MIM) ("MID" or the "Company") today announced its restated results for the three and nine-month per

November 12, 2010 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2010 THIRD QUARTER RESULTS AND MANAGEMENT CHANGES

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 Third Quarter Report 2010 MI Developments Inc. MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2010 THIRD QUARTER RESULTS AND MANAGEMENT CHANGES November 11, 2010, Aurora, Ontario, Canada — MI Developments Inc. (TSX: MIM.A, MIM.B; NYSE: MIM) ("MID" or the "Company") today an

November 12, 2010 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Rocco Liscio, the Executive Vice-President and Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interim filings") of MI Developments Inc.

November 12, 2010 EX-99.1

MI DEVELOPMENTS RECEIVES PROPOSAL FOR ITS RACING ASSETS FROM MINOR RACING, LLC

Exhibit 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 MI DEVELOPMENTS RECEIVES PROPOSAL FOR ITS RACING ASSETS FROM MINOR RACING, LLC November 10, 2010, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) announced that it has received a proposal from Minor Racing, LLC to acquire from MID for a price in the range of US$150 million to US$170 mill

November 12, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of November 2010 Commission File Number : 001-31728 MI DEVELOPM

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of November 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offi

November 12, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of November 2010 Commission File Number: 001-31728 MI DEVELOPME

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.

November 12, 2010 EX-99.2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Dennis Mills, the Vice-Chairman and Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interim filings") of MI Developments Inc. (the "issue

November 4, 2010 CORRESP

RE:

MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario Canada L4G 7A9 Tel: (905) 726.7507 Fax: (905) 713.6332 November 4, 2010 Division of Corporation Finance United States Securities and Exchange Commission 100 F Street, N.E. Washington, DC 20549 Attention: Linda Cvrkel and Heather Clark Dear Sir/Madame: RE: MI Developments Inc. (“MID” or the “Company”) Form 40-F for the year ended Decem

November 4, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of November 2010 Commission File Number : 001-31728 MI DEVELOPM

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of November 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offi

November 4, 2010 EX-1

MI DEVELOPMENTS NOTICE OF RELEASE OF THIRD QUARTER 2010 RESULTS

Exhibit 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 MI DEVELOPMENTS NOTICE OF RELEASE OF THIRD QUARTER 2010 RESULTS November 4, 2010, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) will announce its financial results for the third quarter ended September 30, 2010 on Thursday, November 11, 2010 after the close of business. About MID: MID

October 19, 2010 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 16)* MI Developments Inc. (Name of issuer) Class A Subordinate Voting Shares (Title of class of securities

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 16)* MI Developments Inc. (Name of issuer) Class A Subordinate Voting Shares (Title of class of securities) 55304X 10 4 (CUSIP Number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, addr

October 19, 2010 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 17)* MI Developments Inc. (Name of issuer) Class B Voting Shares (Title of class of securities) 55304X 20

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 17)* MI Developments Inc. (Name of issuer) Class B Voting Shares (Title of class of securities) 55304X 20 3 (CUSIP number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, address and tele

October 7, 2010 CORRESP

2

MI Developments Inc. 455 Magna Drive, 2nd Floor Aurora, Ontario Canada L4G 7A9 Tel: (905) 726.7507 Fax: (905) 713.6332 October 7, 2010 Division of Corporation Finance United States Securities and Exchange Commission 100 F Street, N.E. Washington, DC 20549 Attention: Linda Cvrkel and Heather Clark Dear Sir/Madame: RE: MI Developments Inc. (“MID” or the “Company”) Form 40-F for the year ended Decemb

October 5, 2010 SC14D9C

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 SOLICITATION/RECOMMENDATION STATEMENT UNDER SECTION 14(d)(4) OF THE SECURITIES EXCHANGE ACT OF 1934 MI DEVELOPMENTS INC. (Name of Subject Company) MI DEVELOPMENTS INC. (Name of

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 SOLICITATION/RECOMMENDATION STATEMENT UNDER SECTION 14(d)(4) OF THE SECURITIES EXCHANGE ACT OF 1934 MI DEVELOPMENTS INC. (Name of Subject Company) MI DEVELOPMENTS INC. (Name of Person Filing Statement) Class A Subordinate Voting Shares Class B Shares (Title of Class of Securities) 55304X104 55304X203 (CUSIP Number of Class of

October 5, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October, 2010 Commission File Number 001-31728 MI DEVELOP

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October, 2010 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive off

October 5, 2010 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9

Exhibit 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 MI DEVELOPMENTS ADVISED BY ST ACQUISITION CORP. OF ITS INTENTION TO MAKE AN OFFER FOR MID SHARES October 4, 2010, Aurora, Ontario, Canada ? MI Developments Inc. (?MID?) (TSX: MIM.A, MIM.B; NYSE: MIM) announced that it has been advised by ST Acquisition Corp. (the ?Offeror?), a corporation controlled by members of the Stronac

October 5, 2010 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9

Exhibit 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 MI DEVELOPMENTS ADVISED BY ST ACQUISITION CORP. OF ITS INTENTION TO MAKE AN OFFER FOR MID SHARES October 4, 2010, Aurora, Ontario, Canada – MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) announced that it has been advised by ST Acquisition Corp. (the “Offeror”), a corporation controlled by members of the Stronac

October 4, 2010 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 15)* MI Developments Inc. (Name of issuer) Class A Subordinate Voting Shares (Title of class of securities

Amendment No. 15 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 15)* MI Developments Inc. (Name of issuer) Class A Subordinate Voting Shares (Title of class of securities) 55304X 10 4 (CUSIP number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880

October 4, 2010 SC TO-C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )* MI Developments Inc. (Name of Subject Company (Issu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )* MI Developments Inc. (Name of Subject Company (Issuer)) ST ACQUISITION CORP. (Names of Filing Persons (Offeror)) Class A Subordinate Voting Shares Class B Voting Shares (Title of Classes of Securities)

October 4, 2010 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 16)* MI Developments Inc. (Name of issuer) Class B Voting Shares (Title of class of securities) 55304X 20

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 16)* MI Developments Inc. (Name of issuer) Class B Voting Shares (Title of class of securities) 55304X 20 3 (CUSIP number) Kenneth G. Alberstadt Akerman Senterfitt LLP 335 Madison Avenue, Suite 2600 New York, NY 10017 (212) 880-3817 (Name, address and tele

August 13, 2010 EX-99.2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Dennis Mills, the Vice-Chairman and Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interim filings") of MI Developments Inc. (the "issue

August 13, 2010 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2010 SECOND QUARTER RESULTS

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 Second Quarter Report 2010 MI Developments Inc. MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 MI DEVELOPMENTS ANNOUNCES 2010 SECOND QUARTER RESULTS August 12, 2010, Aurora, Ontario, Canada — MI Developments Inc. (TSX: MIM.A, MIM.B; NYSE: MIM) ("MID" or the "Company") today announced its results for

August 13, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of August 2010 Commission File Number: 001-31728 MI DEVELOPMENT

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.

August 13, 2010 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document EXHIBIT 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Rocco Liscio, the Executive Vice-President and Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interim filings") of MI Developments Inc.

August 5, 2010 EX-99.1

MI DEVELOPMENTS NOTICE OF RELEASE OF SECOND QUARTER 2010 RESULTS

Exhibit 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 MI DEVELOPMENTS NOTICE OF RELEASE OF SECOND QUARTER 2010 RESULTS August 5, 2010, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) will announce its financial results for the second quarter ended June 30, 2010 on Thursday, August 12, 2010 after the close of business. About MID: MID is a re

August 5, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of August 2010 Commission File Number : 001-31728 MI DEVELOPMEN

6-K 1 a10-1538716k.htm 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of August 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of

July 1, 2010 EX-99.1

MI DEVELOPMENTS ANNOUNCES JOINT VENTURE CLOSING WITH PENN NATIONAL GAMING

EXHIBIT 99.1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 MI DEVELOPMENTS ANNOUNCES JOINT VENTURE CLOSING WITH PENN NATIONAL GAMING July 1, 2010, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) today closed the previously announced joint venture with Penn National Gaming, Inc. to own and operate the Maryland Jockey Club, including its racing op

July 1, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of July 2010 Commission File Number : 001-31728 MI DEVELOPMENTS

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of July 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices)

May 17, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of May 2010 Commission File Number : 001-31728 MI DEVELOPMENTS

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of May 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices)

May 17, 2010 EX-99.1

CHURCHILL DOWNS INCORPORATED AND MI DEVELOPMENTS INC. ANNOUNCE DISSOLUTION OF TRACKNET MEDIA VENTURE

Exhibit 99.1 FOR IMMEDIATE RELEASE Contact: Liz Harris Vice President, Communications Churchill Downs Incorporated (502) 636-4474 (office) Dennis Mills Chief Executive Officer MI Developments Inc. (905) 726-7614 (office) CHURCHILL DOWNS INCORPORATED AND MI DEVELOPMENTS INC. ANNOUNCE DISSOLUTION OF TRACKNET MEDIA VENTURE LOUISVILLE, Ky./AURORA, Canada (May 14, 2010) - Churchill Downs Incorporated (

May 14, 2010 EX-99.1

EX-99.1

EXHIBIT 99.1 Form 51-102F3 MATERIAL CHANGE REPORT ITEM 1: REPORTING ISSUER MI Developments Inc. (“MID”) 455 Magna Drive Aurora, ON L4G 7A9 ITEM 2: DATE OF MATERIAL CHANGE May 7, 2010 ITEM 3: PRESS RELEASE On May 7, 2010, a press release (the “Press Release”) describing the material change was issued by MID and delivered to the Ontario Securities Commission and the other Canadian securities regulat

May 14, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of May 2010 Commission File Number : 001-31728 MI DEVELOPMENTS

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of May 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices)

May 11, 2010 EX-1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2010 FIRST QUARTER RESULTS

QuickLinks - Click here to rapidly navigate through this document Exhibit 1 First Quarter Report 2010 MI Developments Inc.

May 11, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.

May 10, 2010 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2010 FIRST QUARTER RESULTS

EX-99.1 2 a2198614zex-991.htm EXHIBIT 99.1 QuickLinks - Click here to rapidly navigate through this document MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2010 FIRST QUARTER RESULTS May 7, 2010, Aurora, Ontario, Canada — MI Developments Inc. (TSX: MIM.A, MIM.B; NYSE: MIM) ("MID" or the "Company") today announce

May 10, 2010 EX-99.2

Three Months Ended March 31, (in millions, except per share information) 2010 2009 Change Rental revenues $ 43.8 $ 40.4 8% Interest and other income from MEC(1) 0.8 13.5 (94% ) Revenues 44.6 53.8 (17% ) Net income(2) 15.1 25.2 (40% ) Funds from opera

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.2 Management's Discussion and Analysis of Results of Operations and Financial Position For the Three-month Period ended March 31, 2010 Management's Discussion and Analysis of Results of Operations and Financial Position ("MD&A") of MI Developments Inc. ("MID" or the "Company") summarizes the significant factors affecting

May 10, 2010 EX-99.4

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.4 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Dennis Mills, the Vice-Chairman and Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interim filings") of MI Developments Inc. (the "issue

May 10, 2010 EX-99.3

As at March 31, 2010 December 31, 2009 ASSETS Current assets: Cash and cash equivalents $ 170,948 $ 135,163 Restricted cash (note 3) 458 458 Accounts receivable 1,781 1,796 Income taxes receivable 1,646 1,723 Prepaid expenses and other 553 1,007 175,

Interim Consolidated Financial Statements and Notes For the period ended March 31, 2010 Consolidated Balance Sheets (Refer to note 1 — Basis of Presentation) (U.

May 10, 2010 6-K/A

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K/A REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.

May 10, 2010 EX-99.5

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

EX-99.5 6 a2198614zex-995.htm EXHIBIT 99.5 QuickLinks - Click here to rapidly navigate through this document Exhibit 99.5 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Rocco Liscio, the Executive Vice-President and Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the

May 7, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, D.

May 7, 2010 EX-99.3

As at March 31, 2010 December 31, 2009 ASSETS Current assets: Cash and cash equivalents $ 170,948 $ 135,163 Restricted cash (note 3) 458 458 Accounts receivable 1,781 1,796 Income taxes receivable 1,646 1,723 Prepaid expenses and other 553 1,007 175,

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.3 Interim Consolidated Financial Statements and Notes For the period ended March 31, 2010 Consolidated Balance Sheets (Refer to note 1 — Basis of Presentation) (U.S. dollars in thousands) (Unaudited) As at March 31, 2010 December 31, 2009 ASSETS Current assets: Cash and cash equivalents $ 170,948 $ 135,163 Restricted cash

May 7, 2010 EX-99.5

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

EX-99.5 6 a2198614zex-995.htm EXHIBIT 99.5 QuickLinks - Click here to rapidly navigate through this document Exhibit 99.5 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Rocco Liscio, the Executive Vice-President and Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the

May 7, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of May 2010 Commission File Number : 001-31728 MI DEVELOPMENTS

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of May 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices)

May 7, 2010 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2010 FIRST QUARTER RESULTS

EX-99.1 2 a2198614zex-991.htm EXHIBIT 99.1 QuickLinks - Click here to rapidly navigate through this document MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2010 FIRST QUARTER RESULTS May 7, 2010, Aurora, Ontario, Canada — MI Developments Inc. (TSX: MIM.A, MIM.B; NYSE: MIM) ("MID" or the "Company") today announce

May 7, 2010 EX-99.4

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.4 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Dennis Mills, the Vice-Chairman and Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interim filings") of MI Developments Inc. (the "issue

May 7, 2010 EX-99.2

Three Months Ended March 31, (in millions, except per share information) 2010 2009 Change Rental revenues $ 43.8 $ 40.4 8% Interest and other income from MEC(1) 0.8 13.5 (94% ) Revenues 44.6 53.8 (17% ) Net income(2) 15.1 25.2 (40% ) Funds from opera

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.2 Management's Discussion and Analysis of Results of Operations and Financial Position For the Three-month Period ended March 31, 2010 Management's Discussion and Analysis of Results of Operations and Financial Position ("MD&A") of MI Developments Inc. ("MID" or the "Company") summarizes the significant factors affecting

May 7, 2010 EX-99.1

EX-99.1

Exhibit 99.1 PENN NATIONAL GAMING AND MI DEVELOPMENTS ENTER INTO JOINT VENTURE FOR ASSETS AND OPERATIONS OF MARYLAND JOCKEY CLUB TRACKS, LAUREL PARK AND PIMLICO Wyomissing, PA, Aurora, Ontario, Canada and Baltimore and Laurel, MD (May 7, 2010) — Penn National Gaming, Inc. (PENN: Nasdaq) and MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM), announced today they have agreed to establish a

May 3, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of April 2010 Commission File Number : 001-31728 MI DEVELOPMENT

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of April 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices

May 3, 2010 EX-1

MI DEVELOPMENTS ANNOUNCES THE EFFECTIVE DATE OF THE MAGNA ENTERTAINMENT PLAN OF REORGANIZATION

EX-1 2 a10-91851ex1.htm EX-1 Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 MI DEVELOPMENTS ANNOUNCES THE EFFECTIVE DATE OF THE MAGNA ENTERTAINMENT PLAN OF REORGANIZATION April 30, 2010, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) today announced that the Plan of Reorganization (“Plan”) in respect of Magna Entertainment Corp. (“MEC”

April 27, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of April 2010 Commission File Number : 001-31728 MI DEVELOPMENT

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of April 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices

April 27, 2010 EX-1

MI DEVELOPMENTS ANNOUNCES CONFIRMATION BY THE BANKRUPTCY COURT OF THE MAGNA ENTERTAINMENT PLAN OF REORGANIZATION

Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 MI DEVELOPMENTS ANNOUNCES CONFIRMATION BY THE BANKRUPTCY COURT OF THE MAGNA ENTERTAINMENT PLAN OF REORGANIZATION April 26, 2010, Aurora, Ontario, Canada – MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) today announced that the Plan of Reorganization in respect of Magna Entertainment Corp. (“MEC”) and certain of its

March 31, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of March 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices

March 31, 2010 EX-1

Disclosure Controls and Procedures Report on Internal Control Over Financial Reporting Limitation of Scope of Design of Disclosure Controls and Procedures and Internal Control Over Financial Reporting Changes in Internal Control Over Financial Rep

Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES FOURTH QUARTER AND 2009 RESULTS March 29, 2010, Aurora, Ontario, Canada — MI Developments Inc. (TSX: MIM.A, MIM.B; NYSE: MIM) (“MID” or the “Company”) today announced its results for the three-month period and year ended December 31, 2009. All figures are

March 30, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of March 2010 Commission File Number : 001-31728 MI DEVELOPMENT

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of March 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principal executive offices

March 30, 2010 EX-1

NOTICE OF ANNUAL MEETING OF SHAREHOLDERS

EX-1 2 a2197756zex-1.htm EXHIBIT 1 Use these links to rapidly review the document TABLE OF CONTENTS March 29, 2010 To our Shareholders: On behalf of our Board of Directors and management, I am pleased to invite you to the 2010 Annual Meeting of Shareholders of MI Developments Inc. to be held at Le Parc, 8432 Leslie Street, Thornhill, Ontario, Canada, at 10:00 a.m. (Toronto time) on Friday, May 7,

March 29, 2010 EX-3

Management's Discussion and Analysis of Results of Operations and Financial Position

EX-3 4 a2197686zex-3.htm EXHIBIT 3. MD&A FROM AR QuickLinks - Click here to rapidly navigate through this document Exhibit 3 Management's Discussion and Analysis of Results of Operations and Financial Position For the year ended December 31, 2009 Management's Discussion and Analysis of Results of Operations and Financial Position ("MD&A") of MI Developments Inc. ("MID" or the "Company") summarizes

March 29, 2010 40-F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 40-F

QuickLinks - Click here to rapidly navigate through this document UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 40-F o REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 ý ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2009 Commission File Number 001-31728 MI DEVELOPMENTS INC.

March 29, 2010 EX-4

LETTER TO SHAREHOLDERS

EX-4 5 a2197686zex-4.htm EXHIBIT 4. LETTER TO SHAREHOLDERS QuickLinks - Click here to rapidly navigate through this document EXHIBIT 4 LETTER TO SHAREHOLDERS Dear Shareholders: As you know, the global recession last year had a particularly severe impact on the real estate sector world-wide, and MID was not exempted from the challenges that this presented. Despite this, we are pleased to be able to

March 29, 2010 EX-1

Cautionary Note Regarding Forward-Looking Statements Our Company Corporate Structure and Subsidiaries Overview Three-Year History Business and Operations of Magna, Our Principal Tenant Our Relationship with Magna Magna Entertainment Corp. Intr

EX-1 2 a2197686zex-1.htm EXHIBIT 1. ANNUAL INFORMATION FORM (D2) Exhibit 1 MI Developments Inc. Annual Information Form March 29, 2010 TABLE OF CONTENTS Page Cautionary Note Regarding Forward-Looking Statements 1 Corporate Structure 2 Our Company 2 Corporate Structure and Subsidiaries 2 Company Overview 3 Overview 3 Three-Year History 5 Business and Operations of Magna, Our Principal Tenant 5 Our

March 29, 2010 EX-2

(restated ? note 1(u)) Years ended December 31, 2009 2008 2007 Real Estate Business Gross interest cost $ 14,623 $ 16,004 $ 15,890 Less: interest capitalized (676 ) (833 ) (458 ) Interest expense 13,947 15,171 15,432 Interest income (412 ) (4,976 ) (

QuickLinks - Click here to rapidly navigate through this document Exhibit 2 MANAGEMENT'S RESPONSIBILITY FOR FINANCIAL REPORTING Management of MI Developments Inc.

March 24, 2010 EX-1

MI DEVELOPMENTS ANNOUNCES AMENDMENTS TO MAGNA ENTERTAINMENT PLAN OF REORGANIZATION

Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MI DEVELOPMENTS ANNOUNCES AMENDMENTS TO MAGNA ENTERTAINMENT PLAN OF REORGANIZATION March 23, 2010, Aurora, Ontario, Canada ? MI Developments Inc. (?MID?) (TSX: MIM.A, MIM.B; NYSE: MIM) today announced that the Plan of Reorganization in respect of Magna Entertainment Corp. (?MEC?) and certai

March 24, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of March 2010 Commission File Number : 001-31728 MI DEVELOPMENT

6-K 1 a10-691216k.htm 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of March 2010 Commission File Number : 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of p

February 19, 2010 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February, 2010 Commission File Number 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February, 2010 Commission File Number 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of principa

February 19, 2010 EX-1.1

CUSIP Number

Exhibit 1.1 Date: 19/02/2010 100 University Avenue, 9th floor Toronto ON, M5J 2Y1 www.computershare.com To: All Canadian Securities Regulatory Authorities Subject: MI DEVELOPMENTS INC. Dear Sirs: We advise of the following with respect to the upcoming Meeting of Security Holders for the subject Issuer: Meeting Type : Annual Meeting Record Date for Notice of Meeting : 19/03/2010 Record Date for Vot

February 18, 2010 EX-1

MI DEVELOPMENTS ANNOUNCES FILING OF PLAN OF REORGANIZATION BY MAGNA ENTERTAINMENT

Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MI DEVELOPMENTS ANNOUNCES FILING OF PLAN OF REORGANIZATION BY MAGNA ENTERTAINMENT February 18, 2010, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) today announced that Magna Entertainment Corp. (“MEC”) has filed a Plan of Reorganization, jointly propo

February 18, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: February, 2010 Commission File Number: 001-31728 MI DEVELOPME

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: February, 2010 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

January 12, 2010 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: January, 2010 Commission File Number: 001-31728 MI DEVELOPMEN

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: January, 2010 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

January 12, 2010 EX-1

MID ANNOUNCES SETTLEMENT IN CONNECTION WITH MAGNA ENTERTAINMENT CHAPTER 11 PROCEEDING

EX-1 2 a10-16851ex1.htm EX-1 Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MID ANNOUNCES SETTLEMENT IN CONNECTION WITH MAGNA ENTERTAINMENT CHAPTER 11 PROCEEDING January 11, 2010, Aurora, Ontario, Canada — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) today announced that it, its subsidiary MID Islandi sf. (the “MID Lender

November 12, 2009 EX-99.2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

EX-99.2 3 a2195330zex-992.htm EXHIBIT 99.2 QuickLinks - Click here to rapidly navigate through this document Exhibit 99.2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Dennis Mills, the Vice-Chairman and Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interim fi

November 12, 2009 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

QuickLinks - Click here to rapidly navigate through this document Exhibit 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Rocco Liscio, the Executive Vice-President and Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interim filings") of MI Developments Inc.

November 12, 2009 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: November, 2009 Commission File Number: 001-31728 MI DEVELOPME

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: November, 2009 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

November 12, 2009 EX-99.1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2009 THIRD QUARTER RESULTS

EX-99.1 2 a2195330zex-991.htm EXHIBIT 99.1 QuickLinks - Click here to rapidly navigate through this document Exhibit 99.1 Third Quarter Report 2009 MI Developments Inc. MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2009 THIRD QUARTER RESULTS November 10, 2009, Aurora, Ontario, Canada — MI Developments Inc. (TSX

November 2, 2009 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: November, 2009 Commission File Number: 001-31728 MI DEVELOPME

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: November, 2009 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

November 2, 2009 EX-99.1

MI DEVELOPMENTS NOTICE OF RELEASE OF THIRD QUARTER 2009 RESULTS

Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario, Canada L4G 7A9 Tel: 905-713-6322 Fax: 905-713-6332 MI DEVELOPMENTS NOTICE OF RELEASE OF THIRD QUARTER 2009 RESULTS Aurora, Ontario, Canada, November 2, 2009 – MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) will announce its financial results for the third quarter ended September 30, 2009 on Tuesday, November 10, 2009 afte

October 13, 2009 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 15)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 15)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20 3 (CUSIP Number) Craig Loverock Senior Financial Advisor 337 Magna Drive Aurora, Ontario L4G 7KI (905) 726-7068 Kenneth G. Alberstadt Akerman Senterfi

October 13, 2009 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 14)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 14)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 55304X 10 4 (CUSIP Number) Craig Loverock Senior Financial Advisor 337 Magna Drive Aurora, Ontario L4G 7KI (905) 726-7068 Kenneth G. Alberstadt Aker

October 5, 2009 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 27)*

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 27)* Magna Entertainment Corp. (Name of Issuer) Class A Subordinate Voting Stock (Title of Class of Securities) 559211 10 7 (CUSIP Number) Richard J. Crofts Executive Vice-President, Corporate Development, General Counsel and Secretary MI Developments Inc.

September 22, 2009 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 13)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 13)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 55304X 10 4 (CUSIP Number) Craig Loverock Senior Financial Advisor 337 Magna Drive Aurora, Ontario L4G 7KI (905) 726-7068 Kenneth G. Alberstadt Aker

September 22, 2009 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 14)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 14)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20 3 (CUSIP Number) Craig Loverock Senior Financial Advisor 337 Magna Drive Aurora, Ontario L4G 7KI (905) 726-7068 Kenneth G. Alberstadt Akerman Senterfi

September 18, 2009 EX-1

MI DEVELOPMENTS INC. ANNOUNCES APPOINTMENT OF NEW CHIEF FINANCIAL OFFICER

EX-1 2 a09-269661ex1.htm EX-1 Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MI DEVELOPMENTS INC. ANNOUNCES APPOINTMENT OF NEW CHIEF FINANCIAL OFFICER September 18, 2009, Aurora, Ontario, Canada — MI Developments Inc. (MID) (TSX: MIM.A, MIM.B; NYSE: MIM) announced today that Mr. Rocco Liscio has been appointed by the Board of Directors

September 18, 2009 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: September, 2009 Commission File Number: 001-31728 MI DEVELOPM

6-K 1 a09-2696616k.htm 6-K SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: September, 2009 Commission File Number: 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address

September 15, 2009 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: September, 2009 Commission File Number: 001-31728 MI DEVELOPM

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: September, 2009 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

September 15, 2009 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 25)*

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 25)* Magna Entertainment Corp. (Name of Issuer) Class A Subordinate Voting Stock (Title of Class of Securities) 559211 10 7 (CUSIP Number) Richard J. Crofts Executive Vice-President-Corporate Development, General Counsel and Secretary MI Developments Inc.

September 15, 2009 EX-1

ONTARIO SECURITIES COMMISSION DISMISSES MINORITY SHAREHOLDER APPLICATIONS OSC Rules in Favour of MI Developments Regarding Transactions With Magna Entertainment

Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 ONTARIO SECURITIES COMMISSION DISMISSES MINORITY SHAREHOLDER APPLICATIONS OSC Rules in Favour of MI Developments Regarding Transactions With Magna Entertainment September 14, 2009, Aurora, Ontario, Canada — MI Developments Inc. (MID) (TSX: MIM.A, MIM.B; NYSE: MIM) today announced that the O

August 31, 2009 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 12)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 12)* MI Developments Inc. (Name of Issuer) Class A Subordinate Voting Shares (Title of Class of Securities) 55304X 10 4 (CUSIP Number) Craig Loverock Senior Financial Advisor 337 Magna Drive Aurora, Ontario L4G 7KI (905) 726-7068 Kenneth G. Alberstadt Aker

August 31, 2009 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 13)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20

Schedule 13D Amendment No. 13 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 13)* MI Developments Inc. (Name of Issuer) Class B Voting Shares (Title of Class of Securities) 55304X 20 3 (CUSIP Number) Craig Loverock Senior Financial Advisor 337 Magna Drive Aurora, Ontario L4G 7KI (905) 726-7068 Kenneth

August 27, 2009 SC 13D/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 23)*

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 23)* Magna Entertainment Corp. (Name of Issuer) Class A Subordinate Voting Stock (Title of Class of Securities) 559211 10 7 (CUSIP Number) Richard J. Crofts Executive Vice-President-Corporate Development, General Counsel and Secretary MI Developments Inc.

August 26, 2009 EX-1

EX-1

Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 MID ANNOUNCES CONDITIONAL AMENDMENT TO MAGNA ENTERTAINMENT DIP LOAN August 26, 2009, Aurora, Ontario, Canada — MI Developments Inc. (MID) (TSX: MIM.A, MIM.B; NYSE: MIM) today announced that the terms of the secured debtor-in-possession financing facility being provided by a wholly-owned sub

August 26, 2009 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: August, 2009 Commission File Number: 001-31728 MI DEVELOPMENT

6-K 1 a09-2421716k.htm 6-K SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: August, 2009 Commission File Number: 001-31728 MI DEVELOPMENTS INC. (Exact name of Registrant as specified in its charter) 455 Magna Drive, Aurora, Ontario, Canada L4G 7A9 (Address of

August 13, 2009 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: August, 2009 Commission File Number: 001-31728 MI DEVELOPMENT

QuickLinks - Click here to rapidly navigate through this document SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: August, 2009 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

August 13, 2009 EX-2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

EX-2 3 a2194238zex-2.htm EXHIBIT 2 QuickLinks - Click here to rapidly navigate through this document Exhibit 2 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Dennis Mills, the Vice-Chairman and Chief Executive Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interim filings") of

August 13, 2009 EX-1

MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2009 SECOND QUARTER RESULTS

EX-1 2 a2194238zex-1.htm EXHIBIT 1 QuickLinks - Click here to rapidly navigate through this document Exhibit 1 Second Quarter Report 2009 MI Developments Inc. MI Developments Inc. 455 Magna Drive Aurora, Ontario Canada L4G 7A9 Tel: (905) 713-6322 Fax: (905) 713-6332 MI DEVELOPMENTS ANNOUNCES 2009 SECOND QUARTER RESULTS August 13, 2009, Aurora, Ontario, Canada — MI Developments Inc. (TSX: MIM.A, MI

August 13, 2009 EX-3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

EX-3 4 a2194238zex-3.htm EXHIBIT 3 QuickLinks - Click here to rapidly navigate through this document Exhibit 3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Richard J. Smith, the Executive Vice-President and Chief Financial Officer of MI Developments Inc., certify the following: 1. Review: I have reviewed the interim financial statements and interim MD&A (together, the "interi

August 11, 2009 EX-1

ONTARIO SECURITIES COMMISSION HEARING REGARDING TRANSACTIONS WITH MAGNA ENTERTAINMENT

EX-1 2 a09-216711ex1.htm EX-1 Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario L4G 7A9 Tel (905) 713-6322 Fax (905) 713-6332 ONTARIO SECURITIES COMMISSION HEARING REGARDING TRANSACTIONS WITH MAGNA ENTERTAINMENT August 11, 2009, Aurora, Ontario, Canada — MI Developments Inc. (MID) (TSX: MIM.A, MIM.B; NYSE: MIM) today announced that, at the request of certain MID Class A shareholders,

August 11, 2009 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: August, 2009 Commission File Number: 001-31728 MI DEVELOPMENT

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: August, 2009 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

August 6, 2009 6-K

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: August, 2009 Commission File Number: 001-31728 MI DEVELOPMENT

SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of The Securities Exchange Act of 1934 For the month of: August, 2009 Commission File Number: 001-31728 MI DEVELOPMENTS INC.

August 6, 2009 EX-1

MI DEVELOPMENTS NOTICE OF RELEASE OF SECOND QUARTER 2009 RESULTS

EX-1 2 a09-213961ex1.htm EX-99.1 Exhibit 1 MI Developments Inc. 455 Magna Drive Aurora, Ontario, Canada L4G 7A9 Tel: 905-713-6322 Fax: 905-713-6332 MI DEVELOPMENTS NOTICE OF RELEASE OF SECOND QUARTER 2009 RESULTS Aurora, Ontario, Canada, August 6, 2009 — MI Developments Inc. (“MID”) (TSX: MIM.A, MIM.B; NYSE: MIM) will announce its financial results for the second quarter ended June 30, 2009 on Thu

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