 At the 1958 British Empire and Commonwealth Games, MacKinnon received a gold medal in "eights".He received a silver medal in "eights" at the 1960 Summer Olympics in Rome, as a member of the Canadian team.MacKinnon was inducted into the Canada's Sports Hall of Fame in 1957,
 the BC Sports Hall of Fame in 1966, and into "University of British Columbia Sports Hall of Fame" in 1993, together with the other members of the Olympic gold team.