McKoy came to the international athletics scene in 1982 by winning a gold medal in 110 m hurdles and silver in 4 x 100 m relay at the Commonwealth Games. In the next year McKoy finished fourth at the first World Championships and repeated this place at the 1984 Summer Olympics.
McKoy finished seventh in the hurdles at the 1988 Summer Olympics in Seoul, as he hit a number of hurdles in the final. His compatriot Ben Johnson tested positive for banned substances at the Games. Over the course of the Dubin Inquiry, McKoy was another of Charlie Francis's trainees to admit to doping and he was banned for two years.
McKoy made a come-back at the 1991 World Championships, finishing fourth again in 110 m hurdles. At the Olympic Games in Barcelona, McKoy put his fourth-place streak behind him and won the gold medal in 13.12 seconds. It was the first Canadian Olympic gold medal in track and field since Duncan McNaughton's first-place finish in the high jump competition in 1932. At the 1993 IAAF World Indoor Championships in Toronto he won the 60 m hurdles.
McKoy had emigrated to Austria over the course of his drugs ban and he consequently obtained Austrian citizenship in 1994. He spent the last years of his career competing for his adopted country and set an Austrian record of 13.14 seconds in the 110 m hurdles.
He has since returned to Toronto, where he now works as personal athletic trainer and therapist. He is an older cousin to an athlete in Guyana, Kevin Parker, who runs marathons.Template:Citation needed
|60 metres||6.49||Karlsruhe, Germany||6 March 1993|
|50 metres hurdles||6.25||Kobe, Japan||5 March 1986|
|60 metres hurdles||7.41||Toronto, Ontario, Canada||14 March 1993|
|100 metres||10.08||Villeneuve-d'Ascq, France||2 July 1993|
|110 metres hurdles||13.08||Villeneuve-d'Ascq, France||2 July 1993|
- Mark McKoy at Sporting Heroes
- Newall, Liz. "You're in great company." Clemson World. Summer 2007. pp. 10–12.
Template:Footer Olympic Champions 110 m hurdles Men Template:Footer World Indoor Champions 60m Hurdles Men Template:Footer Commonwealth Champions 110m Hurdles Men Template:Footer Commonwealth Champions 4x100 m Men
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