Magnus Johnson (September 19, 1871 - September 13, 1936) was an American politician. He served in the United States Senate and United States House of Representatives from Minnesota as a member of the Farmer-Labor Party. Johnson was born near Karlstad, Sweden, and his family moved to the United States in 1891.
He served in both the Minnesota House of Representatives and the Minnesota State Senate before being elected to the U.S. Senate to fill the seat opened because of the death of Knute Nelson. Johnson served in the Senate from July 16, 1923 to March 3, 1925. He lost his bid for reelection in 1924. He was elected to the U.S. House of Representatives and served March 4, 1933 to January 3, 1935.