The 2003 Ontario Nokia Cup, Southern Ontario's men's provincial curling championship, was held January 25-February 2 at the Hershey Centre in Mississauga. Ottawa's Bryan Cochrane won his lone provincial championship of his career. His rink of , Ian MacAulay and would represent Ontario at the 2003 Nokia Brier. The event was boycotted by the Wayne Middaugh and Glenn Howard rinks who were still in a dispute with the Canadian Curling Association over receiving a share of Brier revenues.