Mary Beth Stewart

Mary Beth Pauline Stewart (born December 8, 1945), also known by her married name Mary Stewart McIlwaine, is a Canadian former competitive swimmer who swam in High School for the Canadian Dolphins club and competed for Canada in freestyle events at the 1960 and 1964 Olympics. She twice broke the long-course world record in the women's 100-metre butterfly in the early 1960s. A serious student, Mary attended an accelerated program at Kitsilano Secondary School an 8-12 public school known for quality academics and a strong sports program. She planned to attend the University of British Columbia.

Mary studied dance from the age of four. A talented performer, through much of her swimming career from 1956-1963 she was the first person to perform as the University of British Columbia's mascot Leo the Lion at BC Lion home games held at Vancouver’s Empire Stadium. Beginning around the age of 10 she performed jumps, cartwheels, flips and handstands, as Leo the lion primarily during pre-game and half-time intervals. Beginning around 1955, she was tutored in choreography at the Vancouver studio of Grace Macdonald, who worked for the British Columbia Lions coordinating their cheerleaders.

In July 1962, Mary set a world record for the Women's 110-yard butterfly of 1:07.3.

In her final international appearance for Canada at the 1964 Summer Olympics in Tokyo, she finished 28th in the 100 metres Freestyle, 7th in the 4 × 100 metres Freestyle Relay with a combined team time of 4:15.9, 8th in the 100 metres butterfly with a time of 1:10.0 and 6th in the 4 × 100 metres Medley Relay, making the finals with a combined team time of 4:49.9.

International competition highlights At the late November, 1962 Commonwealth Games in Perth, Western Australia, she won the gold medal in the women's 100-metre butterfly, and later toured New Zealand with the team. At the 1963 Pan American Games in São Paulo, Brazil, Stewart enjoyed a four-medal performance, garnering silver medals for her second-place performances in the 100-metre freestyle, 100-metre butterfly, 4x100-metre freestyle relay, and the 4x100-metre medley relay.

In a family with several educators including her mother, Mary worked as a teacher in Vancouver for 38 years. With recognition of her contributions to the sport growing with the passage of time, in 1975 she was admitted to the Canadian Olympic Hall of Fame, and later became a member of the Swimming Canada Circle of Excellence in the Spring of 2025.

Personal life She is the sister of former swimmer Helen Stewart.