Kåre Isaachsen Willoch (; born 3 October 1928) is a Norwegian politician from the Conservative Party. He served as Minister of Trade and Shipping in 1963 and 1965–1970, and as Prime Minister of Norway from 1981 to 1986. Willoch was Chairman of the Conservative Party 1970–1974. He was a member of the Norwegian Parliament from 1957 to 1989. He was also Director of the Nansen Institute.