Kathryn ("Katie") Hoff (born June 3, 1989 in Stanford, California) is an American swimmer.
She trained with Michael Phelps in Baltimore, at North Baltimore Aquatic Club, and is currently trained by Paul Yetter. She holds the American record in the 200 meter individual medley at 2:10.05. She is a strong contender for the 2008 Olympic Games in multiple events. She is best at the 200 and 400 individual medley, though Katie is a very capable swimmer in many events, ranging from any of the four 200s to the 800 free. Katie lost the world record in the 400 meter individual medley to Stephanie Rice in March 2008. However, Hoff reclaimed the world record at the 2008 Olympic trials in Omaha, Nebraska with a time of 4:31.12.
She qualified for the 2004 Summer Olympics, but had a rather disappointing showing in her first Games, placing 7th overall in the Women's 200 metre individual medley and 17th in the 400 metre medley.