Einar Henry Gerhardsen (10 May 1897 – 19 September 1987) was a Norwegian politician who served as the prime minister of Norway from 1945 to 1951, 1955 to 1963 and 1963 to 1965. With a total of 16 years in office, he is the longest serving Prime Minister in Norway since the introduction of parliamentarism. He was the leader of the Labor Party from 1945 to 1965.

Many Norwegians often refer to him as "Landsfaderen" (Father of the Nation); he is generally considered one of the main architects of the post-war rebuilding of Norway after World War II. He also served as the second President of the Nordic Council in 1954.