Killeen is a surname of Irish origin. Notable people with the surname include:
- Caroline Killeen (1926–2014), American activist
- Donald Killeen (1923–1972), Irish-American criminal
- Evans Killeen (born 1936), American baseball player
- 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
- 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
- Mark Killeen, British actor
- Neil Killeen (born 1975), English cricketer
- Oliver Killeen (born 1937), Irish bigamist and fraudster
- 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
- Timothy Killeen (1923–1993), Irish politician
- Tony Killeen (born 1952), Irish politician