Derya Büyükuncu (pronounced [ˈdeɾja ˈbyjycˈundʒu]; born 2 July 1976) is a six-time Olympic backstroke and butterfly swimmer from Turkey.

[3][4] He participated in six consecutive Summer Olympic Games: 1992 Barcelona, 1996 Atlanta, 2000 Sydney, 2004 Athens, 2008 Beijing, 2012 London.

At the age of nine, Büyükuncu became a national swimmer, and won a bronze medal in the 12-year-age category at the 1985 Balkan Swimming Championships held in Bulgaria.

In 1993, he was named the "Male High School Swimmer of the Year" by the National Interscholastic Swimming Coaches Association (NISCA) in the USA.

[3][4][13] Büyükuncu was sentenced to permanent deprivation of rights and an arrest warrant was issued for his post on his Twitter account against President Erdogan, who had coronavirus in 2022.

[14] Derya Büyükuncu participated at the Yok Böyle Dans (Turkish version of Dancing with the Stars) TV Show in 2010 and he got the fourth place.