Terry McDermott was a surprise winner on the 500 m at the 1964 Winter Olympics in Innsbruck when he beat the favourite in that distance, reigning Olympic Champion Yevgeny Grishin, by half a second. His coach at the time was Leo Freisinger, the 500 m bronze medal winner of the 1936 Winter Olympics. McDermott's international career consisted exclusively of the 500 m at the Olympic Winter Games of 1960, 1964, and 1968.
McDermott was inducted in the National Speedskating Hall of Fame on 4 June 1977. At the 1980 Winter Olympics in Lake Placid, McDermott took the Olympic Oath representing the judges. He currently resides in Bloomfield Hills, Michigan. He is married with 5 children and 11 grandchildren.