Gail E. Greenough, CM (born March 7, 1960) is a Canadian equestrian. She was the first woman, the first Canadian, the first North American, the first rider to have zero faults in the competition, and the youngest person ever to win the World Show Jumping Championships. Greenough was champion in 1986 at Aachen, riding a horse named Mr T (Hann).
In 1990, she was made a Member of the Order of Canada.