Hennessy (surname)

Hennessy (or Hennessey) is an Irish surname, being the anglicised form of Ó hAonghusa.

Notable people with the surname include:


 * Arthur Hennessy (1876–1959), Australian pioneer rugby league identity
 * Bill Hennessy (disambiguation)
 * Carly Smithson (née Hennessy, born 1983), Irish singer
 * Christie Hennessy (1945-2007), Irish singer
 * Claire Hennessy (born 1986), Irish novelist
 * Clinton Hennessy (born 1977), Irish sportsperson
 * David Hennessy (1858–1890), police chief of New Orleans
 * Esmé Frances Hennessy (born 1933), South African botanist
 * George Hennessy, 1st Baron Windlesham (1877, 1953), British soldier and Conservative politician
 * Jean Hennessy (1874–1944), French politician and member of the Hennessy family
 * Jacqueline Hennessy (born 1968), journalist
 * Jill Hennessy (born 1968), film and television actress
 * Joe Hennessy (born 1956), former Irish sportsperson
 * Archbishop John Hennessy (1825–1900), head of the Roman Catholic Archdiocese of Dubuque
 * John L. Hennessy (born 1953), American computer scientist and current president of Stanford University
 * John Pope Hennessy (1834–1891), Irish colonial administrator and politician - eighth governor of Hong Kong, fifteenth governor of Mauritius, MP for King's County
 * Josh Hennessy (born 1985), professional ice hockey player
 * Kevin Hennessy (born 1961), Irish retired sportsperson
 * Larry Hennessy (1929–2008), American basketball player
 * Matt Hennessy (born 1997), American football player
 * Matthew Hennessy, Irish computer scientist
 * Miranda Hennessy, British actress and comedian
 * Neil Hennessy (born 1978), musician and music producer/engineer
 * Patrick Hennessy, several people including
 * Patrick Hennessy (painter), (1915–1980), an Irish artist
 * Sir Patrick Hennessy (industrialist), (1898–1981), an Irish-born British industrialist,
 * Peter Hennessy (born 1947), English historian of government
 * Ryan Hennessy (born 1995), Irish singer and musician
 * Séamus Hennessy (hurler, born 1989), Irish sportsperson
 * Swan Hennessy (1866–1929), Irish-American composer resident in Paris
 * Thomas Hennessy (politician), Irish politician
 * Thomas Hennessy (American football) (born 1994), American football player
 * W. Louis Hennessy (born 1955), 4th Circuit Court Associate Judge in Maryland, former Maryland Delegate
 * William Hennessy (disambiguation)