Born in Toronto, Imlach played junior hockey in the OHA for the Toronto Young Rangers (1935–38) and senior hockey with the Toronto Goodyears (1938–40) and the Toronto Marlboros (1940–41). He enlisted in the army during World War II, where he coached for the first time, with an army team in Cornwall, Ontario. He was invited to training camp by the Detroit Red Wings after being discharged, but felt he had put on too much weight and declined.