Onen is a surname. Notable people with the surname include:
Abdulkadir Emin Önen (born 1976), Turkish politician Charles Onen, Ugandan 21st century priest and politician James Onen (born 1975), Ugandan radio presenter Jayden Onen (born 2001), English footballer Zafer Önen (1921– 2013), Turkish film actor
See also Onan (disambiguation), which includes people with the surname