Kay Worthington joined the University of Toronto’s rowing team during her freshman year in 1979, when the women’s program was in only its third year. She became a member of the Canadian national team in the early 1980s and had three consecutive fourth-place finishes in the eights at major tournaments: the 1981 and 1983 World Championships and the 1984 Summer Olympics. She continued to row after he 1983 graduation and switched to the quadruple sculls at the 1985 World Championships, where she placed seventh alongside Heather Hattin, Sarah Ann Ogilvie, and the non-Olympian Carla Pace. Worthington, with Barbara Armbrust, Marilyn Brain, and Silken Laumann, failed to reach the podium in the same event at the 1986 World Championships, and then switched to the single sculls for the 1987 edition, where she placed fourth. Her next stop was the 1988 Summer Olympics, where she and Laumann finished first in the B final of the double sculls and seventh overall.
Worthington retired from the national team after the Games, but remained in rowing shape and staged a comeback in an attempt to qualify for the 1992 Summer Olympics. Not only did she qualify, but she became a double gold medalist, winning the eights alongside Kirsten Barnes, Brenda Taylor, Megan Delehanty, Marnie McBean, Shannon Crawford, Jessica Monroe, Kathleen Heddle, and Lesley Thompson-Willie, and the coxless fours with Barnes, Monroe, and Taylor. In the latter case, Worthington was a last-minute substitute for Jennifer Walinga, who was forced to drop out the day prior to the event due to an injury. Worthington retired permanently after her victories and has worked as a sports commentator, consultant, and stock trader in addition to acquiring a law degree. She was made a member of the Canadian Olympic Hall of Fame in 1994 and Canada’s Sports Hall of Fame in 2013.