George Smith swam competitively for Canada from 1967 to 1971. He won two gold and two silver medals at Edinburgh, Scotland in 1970, setting two new Commonwealth Game records in the 200 and 400 yards individual medleys. He received his silver medals for the 400 and 800 relays. At the 1968 Olympics in Mexico, he placed fifth in the 200 individual medley; tenth in the 400 individual medley; and swam on the Canadian Freestyle Relay team that finished fourth and eighth. In 1974, George Smith was a co-winner of the Canadian Intercollegiate Athletic Union Outstanding Male Swimmer Award.