Hennessey is an Irish surname, being the anglicised form of Ó hAonghusa. Families of this name were found in Kingdom of Uí Failghe and Kingdom of Desmond. Notable people with the surname include:
Brad Hennessey (born 1980), baseball player
Charlotte Hennessey (1873–1928), Canadian actress; mother of Mary Pickford (Gladys Louise Smith), Lottie Pickford and Jack Pickford Dan Hennessey (born 1941), Canadian voice actor Dorothy Hennessey (1913–2008), Roman Catholic religious sister and activist Gwen Hennessey (born 1932), Roman Catholic religious sister and activist John Hennessey, founder of Hennessey Performance Engineering Keith Hennessey, director of the U.S. National Economic Council Terry Hennessey (born 1942), Welsh footballer Wayne Hennessey (born 1987), Welsh footballer
Fictional characters: Alistair Hennessey, fictional rival to the eponymous character of The Life Aquatic with Steve Zissou
See also
Hennessy (surname)