Hannigan is an Irish surname. A spelling variant is Hannegan. Notable people with the surname include:
Hannigan Alyson Hannigan (born 1974), American actress Barbara Hannigan (born 1971), Canadian soprano Ben Hannigan (1943–2021), Irish footballer Dominic Hannigan (born 1965), Irish politician Ed Hannigan (born 1951), American comic book writer and artist Ernie Hannigan (1943–2015), Scottish footballer George Hannigan (born 1987), Irish Gaelic footballer Gord Hannigan (1929–1966), Canadian ice hockey player James Hannigan (born 1971), British composer James Hannigan (bishop) (1928–1994), Irish-born prelate John Hannigan (1938/9–2014), Irish Gaelic footballer Johnny Hannigan (1933–2020), Scottish footballer Joseph Hannigan (1904–1957), Irish politician and medical practitioner Katherine Hannigan (born 1962), American writer Lisa Hannigan (born 1981), Irish singer and songwriter Pat Hannigan (1936–2007), Canadian ice hockey player and television analyst Pat Hannigan (rugby) (1887–1964), New Zealand rugby league footballer Patrick Hannigan (born 1982), American soccer player Ray Hannigan (1927–2020), Canadian ice hockey player Richard Hannigan, Scottish footballer Robert Hannigan (born 1965), senior British civil servant and author Robyn E. Hannigan, American academic in the field of science Steáfán Hannigan, Irish musician, author, composer, audio engineer, musicologist and instrument maker Teresa Hannigan, Canadian film and television editor Thomas M. Hannigan (1940–2018), American businessman and politician
Fictional characters: Miss Agatha Hannigan, fictional character in Annie Mimzy Hannigan, fictional character in Hazbin Hotel Daniel Hannigan (disambiguation), multiple characters
Hannegan Bryan Hannegan, American scientific administrator Edward A. Hannegan (1807–1859), American politician from Indiana Robert E. Hannegan (1903–1949), American politician from Missouri Tom Hannegan (1970–2021), American businessman and politician from Missouri
See also Hanagan, surname Hanigan, surname Hannegan v. Esquire, Inc., 1946 U.S. Supreme Court case Hannegan Peak, Washington Hannegan caldera, Washington