Arthur Byron MacDonald (born July 23, 1950) is an American Canadian swimming coach who helms the Toronto Varsity Blues swim teams at the University of Toronto.
He is a former swimmer who competed for Canada in the 1972 Summer Olympics in Munich, Germany.
MacDonald placed sixth in the final of the men's 100-metre butterfly, and also competed in the preliminary heats of the 200-metre butterfly, but did not advance.
He had suffered an acute hernia at the Opening Ceremonies, two days before competition, but doctors pushed the hernia "back into place".He has coached Varsity Blues swim teams to 17 Canadian Interuniversity Sport championships—nine women's, and eight men's —including most recently, a women's and men's team competition sweep of the 2015-2016 national titles.He also works as a television commentator analyzing major competitions in swimming.
He is a two-time recipient of the Gemini Award for sports play-by-play broadcasting in recognition of his swimming analysis on CBC at the Summer Olympic Games in 2004 and 2008.MacDonald was born in Mississauga, Ontario, but raised in Chicago, Illinois.