Percy Williams was inducted into the Canadian Sports Hall of Fame, and in 1980 was invested with the Order of Canada.

In 1927, while in high school, Williams won the 100yd. (10 sec) and the 220 yd. at the Brockton Point meet. Later that year at a Seattle meet, he ran the 100yd. In 9.9 seconds.

During the 1928 Olympic Trials, Williams won the 100m and 200m and qualified for the Canadian team. He traveled to the Amsterdam Olympics to win the 100m in 10.8 seconds and the 200m in 21.8 seconds. He was the first Canadian double gold medalist for these events.

In 1929, Williams toured Eastern U.S. and Central Canada on the Indoor Circuit. Over the first 21 days, he competed in 9 cities, ran 22 races and won 21. Several of his wins equaled or broke world records.

In July 1929, Williams defeated famous sprinters, Wycoff and Tolan, (both of whom had competed at the Olympics) in a race at the Mid- Summer Carnival and Grand Amateur Athletic Meet at Hastings Park, in Vancouver. He set a world record for the 100m with a time of 10.3 seconds, in Toronto in 1930. In August 1930, Williams won gold in the 100 yards at the first British Empire Games held in Hamilton, Ontario. During the race he pulled a thigh muscle, an injury from which he never fully recovered, and which eventually ended his sprinting career.

Later, he moved on to Captain the Canadian Team at the 1932 Olympic Games in Los Angeles. Although eliminated in the finals of the 100m, he ran on relay team that placed fourth.