James Guy (born 26 November 1995) is an English competitive swimmer who has represented Great Britain in the Olympic Games, the FINA World Championships and the LEN European championships, and England in the Commonwealth Games. Guy specialises in the 200- and 400-metre freestyle, and the 100-metre butterfly. He won two World Championship gold medals in the 200-metre freestyle and 4×200-metre freestyle relay event at the 2015 World Aquatics Championships. In 2016, he won silver in the 4x200m freestyle relay and the 4x100m medley relay at the Rio Olympics in 2016.
Guy was born in Bury to Cath and Andrew Guy. Guy was educated at Forest Preparatory School, Timperley in Trafford, Greater Manchester. When he was 13, he received a swimming scholarship to Millfield in Somerset. He was a member of Trafford Metros swimming club before he moved to Somerset.
Guy won his first major medal at the 2012 European Junior Championships in Antwerp where he finished in the bronze medal position in the 400m freestyle.