Ada MacKenzie’s first tournament victory was the 1919 Canadian Women’s Amateur which she won another four times during her career. Her all-time titles include four Canadian Ladies’ Open Championships (1955, 1960, 1962, 1965), five Canadian Ladies’ Close Championships (1926-1927, 1929, 1931, 1933) and five Canadian Ladies’ Amateur Championships (1919, 1925-1926, 1933, 1935). She was also a medalist and semi-finalist at the 1927 US Women’s Amateur Championships and reached the semi-finals in 1932. MacKenzie competed throughout North America and Bermuda, winning the 16 career titles, her last victory coming at the 1969 Ontario Senior Women’s Amateur. 

MacKenzie started the Ladies Golf Club in Toronto in 1924 inspired by the fact that couldn’t find a club that would let her play on the weekends, her only days off from work, and ultimately, it was the only golf club in North America specifically for women. In 1930, she opened a women’s sportswear store to provide more appropriate golf apparel for women.

MacKenzie was first introduced to sports as a student at Havergal College in Toronto from 1903-11, where she played golf, cricket, basketball, tennis, figure skating and was named athlete of the year three years in a row, winning the Havergal Cup. Upon graduation in 1911, she took a job as a sports instructor at Havergal College until 1914, then worked for the Canadian Bank of Commerce until 1930. 

The many accolades named in her honour include a park in Thornhill, Ontario after having made it her home from 1940-1973, the Ada Mackenzie Trophy for the Senior Canadian Championship of the Canadian Ladies’ Golf Association; the Ada Mackenzie Foundation that gives awards to wheelchair athletes with a disability through the Canadian Wheelchair Sports Association.

In 1933, Mackenzie was the first recipient of the Bobbie Rosenfeld Award as the top Canadian female athlete of the year. She was inducted into the Canada Sports Hall of Fame in 1955, Canadian Golf Hall of Fame and Canadian Olympic Hall of Fame in 1971, Ontario Sports Hall of Fame in 2003 and Ontario Golf Hall of Fame in 2004.