There are a few grocery stores in Ottawa (the ones located near a college or university) that offer 10% off every Tuesday for Students (with a valid student ID card). Some of them do not offer them in the summer months.
These are the stores that I know that offer the discount during the school year.
Hartmans (Bank Street)
McDonough’s (Billings Bridge)
If you are curious about your local grocer if they offer the same deals, give them a call and ask them. If they don’t offer it, ask for the contact number for head office and send them a message letting them know that there is interest in them having a student discount day, it never hurts to ask.