Koutný (feminine Koutná) is a Czech surname. Notable people with the surname include:
Bedřich Koutný (born 1931), Czech boxer Ilona Koutny (born 1953), Hungarian linguist Jan Koutný (1897–1976), Czech gymnast Lajos Koutny (1939–2022), Hungarian ice hockey player Václav Koutný (born 1991), Czech footballer