Henry Martin "Scoop" Jackson (May 31, 1912 – September 1, 1983) was an American lawyer and politician who served as a U.S. representative (1941–1953) and U.S. senator (1953–1983) from the state of Washington. A Cold War liberal and anti-Communist member of the Democratic Party, Jackson supported higher military spending and a hard line against the Soviet Union, while also supporting social welfare programs, civil rights, and labor unions.

Born in Everett, Washington, to Norwegian immigrants, Jackson practiced law in Everett, after graduating from the University of Washington School of Law. He won election to Congress in 1940, and joined the Senate in 1953 after defeating incumbent Republican Party senator Harry P. Cain. Jackson supported the civil rights movement of the 1960s, and authored the National Environmental Policy Act, which helped establish the principle of publicly analyzing environmental impacts. He co-sponsored the Jackson–Vanik amendment, which denied normal trade relations to non-capitalist countries with restrictive emigration policies. Jackson served as chairman of the United States Senate Committee on Energy and Natural Resources from 1963 to 1981. He was twice an unsuccessful candidate for the Democratic Party nomination, in both the 1972 and 1976 presidential elections. While still serving in the Senate, Jackson died in 1983.