Katinka Hosszú (pronounced ; born 3 May 1989) is a Hungarian competitive swimmer, who specializes in individual medley events. She is a three-time Olympic champion and a five-time long-course world champion.
Hosszú is the world record holder in 100 m individual medley, 200 m individual medley (long course and short course), 400 m individual medley (long course and short course), 100 m backstroke (short course) and 200 m backstroke (short course). She is the first swimmer to hold world records in all five individual medley events at the same time. She holds two-thirds of the Hungarian national records. Hosszu was named FINA Swimmer of the Year in 2014, 2015, and 2016, and won SwimSwam's Swammy Award for Female Swimmer of the Year in 2013.