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.^[1] He had suffered an acute hernia at the Opening Ceremonies, two days before competition, but doctors pushed the hernia "back into place".^[2]

He has coached Varsity Blues swim teams to 17 Canadian Interuniversity Sport championships—nine women's, and eight men's ^[3]—including most recently, a women's and men's team competition sweep of the 2015-2016 national titles.^[4]

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.^[5]

MacDonald was born in Mississauga, Ontario, but raised in Chicago, Illinois.^[6]

Commentating as a swimming analyst on CBC's live telecast of 2016 Summer Olympics women's 4 × 200 metre freestyle relay August 10, 2016, he mistakenly uttered on the air an off-the-cuff opinion to his co-commentator Elliotte Friedman. He criticized China's relay second-leg swimmer Ai Yanhan for swimming her first 50-metre split too fast, then consequently due to fatigue, her last 50 metre split too slowly.^[7]

Caught out being unaware that his microphone was still open to air, he said, "The little 14-year-old from China dropped the ball, baby. Too excited. Went out like stink^[8] and died like a pig. Thanks for that."

On the next day, both he,^[9] and the CBC issued an apology for such comments.^[10] The University of Toronto subsequently issued a statement reiterating CBC's apology on his behalf.^[11]