Coiner is a surname. Notable people with the surname include:
Charles Coiner (born 1943), former Idaho state senator Charles T. Coiner (1898–1989), American painter and advertising art director Charlie Coiner (born 1960), American college football coach Ryan Coiner (born 1979), American retired soccer forward
See also Camp Coiner, a United States Forces Korea installation in Seoul, South Korea Coining (disambiguation)