Gilday is a surname. Notable people with the surname include:
John Gilday (1874–1937), Australian politician Leela Gilday, Canadian musician Michael Gilday (speed skater) (born 1987), Canadian short track speed skater Michael M. Gilday, United States Navy admiral Patrick Gilday (1862–1917), American labor leader Cindy Kenny-Gilday (born 1954), Sahtu environmentalist and activist for Indigenous rights in Canada
See also Gildea Kildee