Kasidit Samrej (; born 26 January 2001) is a Thai tennis player. He has a career high ATP singles ranking of world No. 346 achieved on 25 August 2025. He also has a career high ATP doubles ranking of No. 822 achieved on 12 June 2023. He is currently the No. 1 Thai player.
Samrej represents Thailand at the Davis Cup, where he has a W/L record of 10âÂÂ8.
Samrej won the Asia-Pacific Wildcard Playoff for the 2025 Australian Open, making him the first Thai man to compete in the singles event in a Grand Slam tournament since Danai Udomchoke at the 2012 Australian Open. He lost in the first round to fifth seed Daniil Medvedev in five sets.