Jack Keenan had a relatively brief career as a middleweight boxer that began in 1945 and he found early success the following year when he won a novice Golden Glove Championship. His best year, however, was 1948, when he became the Canadian national champion and was therefore selected to represent his country at that year’s Summer Olympics. At the Games, he lost by decision to Mick McKeon of Ireland in the opening round and was eliminated from the tournament. He then embarked upon a professional career in late 1948, but only fought one boxer, winning the first bout, but then losing a subsequent one against the same opponent. He never again competed professionally.