UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): May 8, 2014

MITEL NETWORKS CORPORATION

(Exact Name of Registrant as Specified in its Charter)

350 Legget Drive

Ottawa, Ontario K2K 2W7

(Address of Principal Executive Offices) (Zip Code)

(613) 592-2122

(Registrant’s telephone number, including area code)

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On May 8, 2014, Mitel Networks Corporation (the “Company”) held its Annual and Special Meeting of Shareholders (the “Meeting”). At the Meeting, the Company’s shareholders approved the 2014 Equity Incentive Plan (the “2014 Equity Incentive Plan”) based on the voting results set forth below under Item 5.07. The 2014 Equity Incentive Plan had previously been approved by the Company’s Board of Directors on March 25, 2014.

The 2014 Equity Incentive Plan replaces the Company’s existing equity incentive plan (the “2006 Equity Incentive Plan”), which was due to expire in 2016. Rather than amending the 2006 Equity Incentive Plan to extend the term and to replenish the pool of common shares available for future awards, the Company wishes to adopt the 2014 Equity Incentive Plan. The 2014 Equity Incentive Plan is substantially similar to the 2006 Equity Incentive Plan, except that the number of common shares available for grant under the 2014 Equity Incentive Plan has been fixed at 8,900,000 common shares and the term of the 2014 Equity Incentive Plan will run until 2024.

For a description of our 2014 Equity Incentive Plan, please see Ordinary Resolution No. 1 in our proxy statement for the Meeting filed with the Securities and Exchange Commission on April 4, 2014, which description is incorporated herein by reference. Such description is qualified in its entirety by reference to the full text of the 2014 Equity Incentive Plan, a copy of which is attached to this Form 8-K and incorporated by reference herein.

On May 8, 2014 the Company held its Meeting. As of the March 19, 2014 record date for the determination of the stockholders entitled to notice of, and to vote at, the Meeting, 98,811,852 shares of the Company’s common stock were outstanding and eligible to vote. A total of 84,979,411 shares voted in person or by proxy at the Meeting. The results of the matters voted on by shareholders at the Meeting are as follows:

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: May 9, 2014

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