The 2003 CIS football season began on August 29, 2003, and concluded with the 39th Vanier Cup national championship on November 22 at the SkyDome in Toronto, Ontario, with the Laval Rouge et Or winning their second championship. Twenty-seven universities across Canada competed in CIS football this season, the highest level of amateur play in Canadian football, under the auspices of Canadian Interuniversity Sport (CIS).