László Cseh (pronounced [ˈlaːsloː ˈt͡ʃɛ]; born 3 December 1985) is a retired Hungarian competitive swimmer and six-time Olympic medalist.

In 2020, Braden Keith of SwimSwam nominated him as number 1 within top 10 male swimmers who have never won Olympic gold.

At the 2010 European Championships, Cseh held off Markus Rogan for gold in the 200 m individual medley, winning the event for the third time.

Cseh narrowly failed to reach the final of the 400 meter individual medley, coming in 9th position in the semi-finals.

Cseh did add to his Olympic medal count with a bronze in the 200 meter individual medley, touching the wall in a time of 1:56.22, behind Phelps (gold – 1:54.27) and Lochte (silver – 1:54.90).

At the 2015 World Aquatics Championships, Cseh finally won another gold, 10 years after his first, by winning the 200m butterfly in 1:53.48, 0.2 seconds ahead of Chad le Clos.

In 100 m butterfly he finished 2nd along with rivals Michael Phelps and Chad le Clos, where Singaporean Joseph Schooling won the race with a new Olympic record.