Kathryn ("Kathy") Ann Watt (born 11 September 1964) is an Australian racing cyclist who won two medals at the 1992 Summer Olympics in Barcelona, Spain (gold in the road race, and silver in the pursuit). She has won 24 national championships in road racing, track racing, and mountain bike, four Commonwealth Games gold medals, and came third in the world time trial championship. She was made a life member of Blackburn Cycling Club in 1990. She was an Australian Institute of Sport scholarship holder.

The daughter of marathoner Geoff Watt, Kathy Watt turned first to running, winning the national junior 3 km championship. She began to train on a bike after achilles tendon problems. For a while, she competed in duathlon (running and cycling), but found she was a better cyclist than runner.

In 1996, Watt was in a legal dispute with the Australian Cycling Federation over who would race the pursuit in the Olympic Games. Watt had been told that she would be but was replaced a few days before the event by Lucy Tyler-Sharman. Watt appealed to the International Court of Arbitration for Sport, claiming a breach of contract. The court ordered Watt to be reinstated in the race.

In 2000, Watt again became involved in a controversy over a selection, but this time she was not successful in her appeal to the CAS.

She retired after 2000 but came back three years later but was not successful in an attempt to qualify for the 2004 Olympics. After another retirement, Watt worked as a coach and personal trainer. However, she made another comeback to qualify for the 2006 Commonwealth Games in Melbourne, where she won a silver medal in the time trial. In January 2006, she won the time trial section of the Australian open road championship in Buninyong, Ballarat.

Watt holds a Bachelor of Science degree from the University of Melbourne, with a major in physiology and pathology. She studied nutrition, anatomy, and physiotherapy. She attended Tintern Church of England Girls' Grammar, now Tintern Grammar.

In 2015, she was an inaugural Cycling Australia Hall of Fame inductee.