Exhibit 99.2

Annual Meeting Greenbrook TMS Inc. (the “Company”) WHEN: WHERE: PROXY FORM CONTROL NO.:➔ SCAN TO VIEW MATERIAL AND VOTE NOW STEP 1 REVIEW YOUR VOTING OPTIONS BY TELEPHONE: YOU MAY ENTER YOUR VOTING INSTRUCTIONS BY TELEPHONE AT: ENGLISH: 1-800-474-7493 OR FRENCH: 1-800-474-7501 BY MAIL: THIS PROXY FORM MAY BE RETURNED BY MAIL IN THE ENVELOPE PROVIDED. REMINDER: PLEASE REVIEW THE INFORMATION / PROXY CIRCULAR BEFORE VOTING. ONLINE: VOTEAT PROXYVOTE.COM USINGYOUR COMPUTER OR MOBILE DATA DEVICE. YOUR CONTROL NUMBER IS LOCATED BELOW. V502122020 PROXY DEPOSIT DATE: June 16, 2023 at 5:00 pm EDT The control number has been assigned to you to identify your shares for voting. You must keep your control number confidential and not disclose it to others other than when you vote using one of the voting options set out on this form. Should you send this form or provide your control number to others, you are responsible for any subsequent voting of, or subsequent inability to vote, your shares. INSTRUCTIONS: 1. This Form of Proxy is solicited by and on behalf of management of the issuer. 2. You have the right to appoint a person, who need not be a shareholder, other than the person(s) specified on the other side of this form to attend and act on your behalf at the Meeting. If you wish to appoint a person: • Write the name of your designate on the “Appointee” line and provide a unique APPOINTEE IDENTIFICATION NUMBER for your Appointee to access the Virtual Meeting in the space provided on the other side of this form, sign and date the form, and return it by mail, or • Go to ProxyVote.com and insert the name of your designate in the “Change Appointee(s)” section and provide a unique APPOINTEE IDENTIFICATION NUMBER on the voting site for your Appointee to access the Virtual Meeting. You MUST provide your Appointee the EXACT NAME and EIGHT CHARACTER APPOINTEE IDENTIFICATION NUMBER to access the Virtual Meeting. Appointees can only be validated at the Virtual Meeting using the EXACT NAME and EIGHT CHARACTER APPOINTEE IDENTIFICATION NUMBER you enter. IF YOU DO NOT CREATE AN EIGHT CHARACTER APPOINTEE IDENTIFICATION NUMBER AND PROVIDE IT TO YOUR APPOINTEE, YOUR APPOINTEE WILL NOT BE ABLE TO ACCESS THE VIRTUAL MEETING. 3. This Form of Proxy confers discretionary authority to vote on amendments or variationsto the mattersidentified in the notice of the Meeting and with respect to other mattersthat may properly be brought before the Meeting or any adjournment or postponement thereof. This Form of Proxy will not be valid and not be acted upon or voted unless it is completed and delivered as outlined herein. 4. If the shares are registered in the name of more than one owner (for example, joint ownership, trustees, executors, etc.), then all those registered should sign this Form of Proxy. If you are voting on behalf of a corporation or another individual, documentation evidencing your power to sign this Form of Proxy with signing capacity stated may be required. 5. In order to expedite your vote, you may use the Internet or a touch-tone telephone, and entering the control number noted above. The Internet or telephone voting service is not available on the day of the Meeting. The telephone system cannot be used if you designate another person to attend on your behalf. If you vote by Internet or telephone, do not mail back this Form of Proxy. 6. If the Form of Proxy is not dated, it will be deemed to bear the date on which it was mailed to the shareholder. 7. This Form of Proxy will be voted as directed by the shareholder. If no voting preferences are indicated on the reverse, this Form of Proxy will be voted as recommended on the reverse of this form or as stated in the management proxy circular, except in the case of your appointment of an Appointee. 8. Unless prohibited by law or you instruct otherwise, your Appointee(s) will have full authority to attend and otherwise act at, and present matters to the Meeting and any adjournment or postponement thereof, and vote on all matters that are brought before the Meeting or any adjournment or postponement thereof, even if these matters are not set out in this form or in the management proxy circular. 9. If these voting instructions are given on behalf of a body corporate,set out the full legal name of the body corporate, and the name and position of the person giving voting instructions on behalf of the body corporate. 10. If the items listed in the management proxy circular are different from the items listed on the other side of this form, the management proxy circular will be considered correct. 11. This Form of Proxy should be read in conjunction with the accompanying management proxy circular. Tuesday, June 20, 2023 at 10:00 am EDT www.virtualshareholdermeeting.com/GTMS2023 PLEASE SEE OVER

STEP 4 THIS DOCUMENT MUST BE SIGNED AND DATED SIGNATURE(S) *INVALID IF NOT SIGNED* MMD D Y Y FOR FOR WITHHOLD FOR WITHHOLD FOR WITHHOLD FOR WITHHOLD VOTING RECOMMENDATIONS ARE INDICATED BY OVER THE BOXES (FILL IN ONLY ONE BOX “ ” PER ITEM IN BLACK OR BLUE INK) STEP 3 COMPLETE YOUR VOTING DIRECTIONS HIGHLIGHTED TEXT ITEM(S): FOR WITHHOLD FOR WITHHOLD 1B Election of Director: Colleen Campbell 1C Election of Director: Sasha Cucuz 1D Election of Director:Adrienne Graves, Ph.D. 1E Election of Director: Benjamin Klein 1F Election of Director: Bill Leonard 1G Election of Director: Frank Tworecke 1H Election of Director: Elias Vamvakas 1A Election of Director: Brian P. Burke FOR WITHHOLD CONTROL NO.: ➔ PROXY FORM ACCOUNT NO: CUSIP: CUID: RECORD DATE: PROXY DEPOSIT DATE: MEETING DATE: MEETING TYPE: STEP 2 APPOINT A PROXY (OPTIONAL) APPOINTEE(S): E-R3 MAXIMUM 22 CHARACTERS - PLEASE PRINT CLEARLY PLEASE PRINT APPOINTEE NAME INSIDE THE BOX CREATE AN EIGHT (8) CHARACTER IDENTIFICATION NUMBER FOR YOUR APPOINTEE ➔ ➔ MUST BE EIGHT CHARACTERS IN LENGTH - PLEASE PRINT CLEARLY WITHHOLD Change Appointee If you wish to designate another person to attend, vote and act on your behalf at the Meeting, or any adjournment or postponement thereof, other than the person(s) specified above, go to www.proxyvote.com or print your name or the name of the other person attending the Meeting in the space provided herein and provide a unique APPOINTEE IDENTIFICATION NUMBER USING ALL BOXES for your Appointee to access the Virtual Meeting. You may choose to direct how your Appointee shall vote on matters that may come before the Meeting or any adjournment or postponement thereof. Unless you instruct otherwise your Appointee will have full authority to attend, vote, and otherwise act in respect of all matters that may come before the Meeting or any adjournment or postponement thereof, even if these matters are not set out in the proxy form or the circular for the Meeting. You can also change your Appointee online at www.proxyvote.com. You MUST provide yourAppointee the EXACT NAME and an EIGHT (8) CHARACTERAPPOINTEE IDENTIFICATION NUMBER to accesstheVirtual Meeting. Appointeescan only be validated at the Virtual Meeting using the EXACT NAME and EIGHT (8) CHARACTER APPOINTEE IDENTIFICATION NUMBER you enter below. Sasha Cucuz, or failing him, Bill Leonard May 5, 2023 June 16, 2023 at 5:00 pm EDT Tuesday, June 20, 2023 at 10:00 am EDT Annual Meeting Greenbrook TMS Inc. (the “Company”) ELECTION OF DIRECTORS: 34 FOR WITHHOLD An ordinary resolution appointing KPMG LLP, Chartered Professional Accountants,Licensed Public Accountants, as auditors of the Company for the ensuing year and authorizing the directors to fix the auditors’ remuneration. 02