Fortinet, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A INFORMATION

PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE

SECURITIES EXCHANGE ACT OF 1934

(AMENDMENT NO. )

Check the appropriate box:

FORTINET, INC.

(Name of Registrant as Specified in Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

NOTICE OF 2026 ANNUAL MEETING OF STOCKHOLDERS

Dear Fortinet Stockholder:

Notice is hereby given that the 2026 Annual Meeting of Stockholders (the “2026 Annual Meeting”) of Fortinet, Inc., a Delaware corporation (“Fortinet,” “we,” “us” or “our”), will be held on Friday, June 12, 2026, at 10:00 a.m. Pacific time, in a virtual-only format, for the following purposes:

1. To elect the nine director nominees listed in the accompanying proxy statement to serve for a one-year term expiring at Fortinet’s 2027 Annual Meeting of Stockholders and until their respective successors have been duly elected and qualified.

2. To ratify the appointment of Deloitte & Touche LLP as Fortinet’s independent registered public accounting firm for the fiscal year ending December 31, 2026.

3. An advisory vote to approve named executive officer compensation.

4. To transact such other business proposals, if properly presented before the meeting.

We believe that a virtual stockholder meeting allows better access to those who may want to attend by providing for greater stockholder attendance and participation from any location around the world, and therefore we have chosen this over an in-person meeting. This approach also lowers costs and aligns with our broader sustainability goals.

The preceding items of business are more fully described in the proxy statement accompanying this notice. Any action on the items of business described above may be considered at the 2026 Annual Meeting at the time and on the date specified above or at any time and date to which the 2026 Annual Meeting may be properly adjourned or postponed. Only stockholders of record at the close of business on April 17, 2026 are entitled to notice of, and to vote at, the 2026 Annual Meeting.

We have elected to provide access to our proxy materials over the internet. Accordingly, stockholders of record at the close of business on April 17, 2026 will receive a Notice of Internet Availability of Proxy Materials and may vote at the 2026 Annual Meeting and any meetings pursuant to postponements or adjournments of the 2026 Annual Meeting. We expect to mail the Notice of Internet Availability of Proxy Materials on or about April 30, 2026.

Your vote is very important. Whether or not you plan to attend the 2026 Annual Meeting, we encourage you to read the proxy statement and vote as instructed in the Notice of Internet Availability of Proxy Materials or vote on the internet or by telephone as soon as possible. Alternatively, you may follow the procedures outlined in the Notice of Internet Availability of Proxy Materials to request a paper copy of the proxy materials, which include a proxy card to submit your vote by mail. For specific instructions on how to vote your shares, please refer to the section entitled “Questions and Answers About the 2026 Annual Meeting and Procedural Matters” and the instructions on the Notice of Internet Availability of Proxy Materials.

Thank you for your ongoing support of Fortinet.

By Order of the Board of Directors,

Ken Xie

Chief Executive Officer and Chairman of the Board of Directors

Sunnyvale, California

FOR THE 2026 ANNUAL MEETING OF STOCKHOLDERS