Gunnar Ellefsen (7 August 1930 - 12 April 1997) was a Norwegian politician for the Labour Party. He was educated as a teacher and was the principal (bestyrer, later rektor) of Mesterfjellet school 1967-1977.
Ellefsen served three terms as Vestfold's deputy representative to the Norwegian Parliament: 1961–1965, 1965–1969 and 1969–1973.
He was the mayor of Larvik from 1972 to 1983.