Gustav Natvig-Pedersen took his M.A. (Cand. Philol.) in 1919. He later studied at the London School of Economics (1928) and Brookwood Labor College, New York (1932). From 1919 he held positions as teacher and principal at Stavanger Katedralskole and from 1946 until 1962 he was principal at St. Svithuns skole in the same city.
Natvig-Pedersen was elected to the City Council in 1923 and became chairman of the local branch of the Labour Party in 1925. He was a member of the Storting in 1937-1953, its Vice-President in 1946-1949, and President in 1949-1953. He belonged to the left wing of the Labour Party. He was a member of the Norwegian Nobel Committee in 1949-1965.