Douglas Bennett started canoeing after he grew frustrated with his lack of progress as a competitive swimmer. A Canadian champion several times from 1934 to 1939, he qualified for the 1940 Olympic Games which were not held due to the Second World War. He finally became an Olympian at London 1948 where he won silver in the C-1 1000m and finished fourth in the C-2 1000m with partner Harry Poulton.