Hynes is an Irish surname, anglicised from the Gaelic Ó hEidhin. Notable people with surname include:
Eidhean mac Cléireach, fl. 800, ancestor of the Ó hEidhin/Hynes family of south County Galway
Andrew Hynes (1750–1800), founder of Elizabethtown, Kentucky
Charles J. Hynes, former District Attorney of Kings County, New York
Daniel Hynes (born 1968), Comptroller of the State of Illinois
Devonte Hynes, member of the band Test Icicles
Frally Hynes, third wife of American singer-songwriter Ben Folds
Garry Hynes, award-winning Irish theatre director
Jessica Hynes (born 1972), English actress and writer, most renowned as one of the stars of the UK sitcom Spaced
James Hynes (born 1955), contemporary American novelist
John Hynes (politician) (1897–1970), Massachusetts politician, mayor of Boston 1950-1960
Jon Hynes, American classical concert pianist
Laurence Hynes Halloran (1765–1831), pioneer schoolteacher and journalist in Australia
Marc Hynes (born 1978), British race car driver
Martin Hynes, American screenwriter, director, actor and producer of independent films
Mary Hynes (broadcaster), Canadian radio and television broadcaster
Peter Hynes (born 1983), Irish footballer
Ron Hynes, folk singer-songwriter from Newfoundland
Tyler Hynes (born 1986), Canadian actor
Fictional characters:
Joe Hynes, character in James Joyce's novel Ulysses