Killeen is a surname of Irish origin. Notable people with the surname include:
Brian Killeen (1911–1993), New Zealand rugby union player
Caroline Killeen (1926–2014), American activist
Danny Killeen (1933–2017), American sailor
Donald Killeen (1923–1972), Irish-American criminal
Evans Killeen (born 1936), American baseball player
George Killeen (1884–1933), Irish rugby union player
Gerry Killeen (born 1961), Irish Gaelic footballer
Graham Killeen (born 1980), American filmmaker and critic
Gretel Killeen (born 1963), Australian television personality
Henry Killeen (1872–1916), American baseball player
J. J. Killeen (born 1981), American golfer
James Jerome Killeen (1917–1978), American Roman Catholic bishop
Jason Killeen (born 1980), Irish basketball player
Johanne Killeen, American chef, restaurant owner and cookbook author
John Killeen (1920–2005), Irish hurler
Len Killeen (1938–2011), South African rugby league footballer
Lewis Killeen (born 1982), English football (soccer) player
Liam Killeen (born 1982), English professional mountain biker
Luke Killeen (born 2005), Australian speedway rider
Mark Killeen, British actor
Neil Killeen (born 1975), English cricketer
Oliver Killeen (born 1937), Irish bigamist and fraudster
Paul Killeen (1903–1991), Australian rules footballer
Paul Killeen (hurler) (born 1994), Irish hurler
Peter Richard Killeen (born 1942), American psychologist
Richard Killeen (born 1946), New Zealand painter, sculptor and digital artist
Ryan Killeen (born 1983), American football (American football) player
Siobhán Killeen (born 1995), Irish association football player
Tiernan Killeen (born 2003), Irish hurler
Timothy Killeen (1923–1993), Irish politician
Timothy L. Killeen (born 1952), British American geophysicist, space physicist, professor, and university administrator
Tony Killeen (born 1952), Irish politician