UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 14A

(Rule 14a-101)

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

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Gladstone Commercial Corporation

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Your Vote Counts! GLADSTONE COMMERCIAL CORPORATION 2024 Annual Meeting Vote by May 1, 2024 11:59 PM ET GLADSTONE COMMERCIAL CORPORATION 1521 WESTBRANCH DRIVE, SUITE 100 MCLEAN, VA 22102 V28327-P04148 You invested in GLADSTONE COMMERCIAL CORPORATION and it’s time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy material for the stockholders meeting to be held on May 2, 2024. Get informed before you vote View the Notice and Proxy Statement and Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 18, 2024. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. Smartphone users Point your camera here and vote without entering a control number Vote Virtually at the Meeting* May 2, 2024 11:00 a.m. ET Virtually at: www.virtualshareholdermeeting.com/GOOD2024 *Please check the meeting materials for any special requirements for meeting attendance.

Vote at www.ProxyVote.com THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. Voting Items Board Recommends 1. Election of Directors Nominees: 01) Walter H. Wilkinson For 02) Paula Novara 2. To ratify our Audit Committee’s selection of PricewaterhouseCoopers LLP as our independent registered public accounting firm for our fiscal year ending December 31, 2024. For NOTE: To transact such other business as may properly come before the meeting or any adjournment or postponement thereof. Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Delivery Settings”. V28328-P04148