The Ontario Medal for Good Citizenship is an honorary medal produced by the Canadian Province of Ontario. It was established by the Government of Ontario in 1973 to recognize people who, through exceptional long-term efforts, have made outstanding contributions to the well being of their communities and whose assistance is given without expectation of remuneration or reward. Typically, eleven to thirteen medals are awarded each year.

Recipients of the medal must be residents of Ontario. No elected federal, provincial or municipal representative may be awarded the Medal while such person remains in office.

Recipients of the medal are entitled to use the postnominal letters O.M.C.