Get certified copies of your divorce decree, birth certificate, marriage certificate and your copy of the Election to Change Surname form from when you married.
Contact the Office of the Registrar General at 800-461-2156 if you live outside Toronto. Call 416-325-8305 if you're in Toronto. Tell the representative you want to change your name because of a divorce. You'll be asked "Yes" or "No" questions about your martial status, your place of birth and what your birth certificate currently says. Answer all questions. The office will send you an Election to Resume Former Surname form.
Complete the Election to Resume Former Surname form. You'll need information about your marriage and divorce, your address, birth date and place of birth. Attach the certified copies to the form.
Prepare the filing fee. Make the payment out to the Office of the Registrar General.
Mail the form, the payment and the attached documents to: Office of the Registrar General c/o Ontario Government Building PO Box 4600 189 Red River Rd Thunder Bay, ON P7B 6L8.