Walter Philip Reuther (b. September 1, 1907, Wheeling, West Virginia - d. May 10, 1970, Pellston, Michigan) was an American labor leader. The son of a socialist brewery worker from West Virginia, he was the most ambitious and successful of three brothers who all went into the United Auto Workers (UAW). Walter rose from the rank-and-file of the UAW in West Side Detroit, Michigan in the 1930s, then took power in the bruising intra-union political battles in the UAW in the 1940s. His rise to power ended the internecine warfare, but also marked the end of truly contested elections for union office at the international level within the UAW. From that point forward the UAW was a one-party union.

Reuther delivered contracts for his members while keeping the UAW active in the liberal wing of the Democratic party. Toward the end of his life, however, when he took the UAW out of the AFL-CIO for a short-lived alliance with the Teamsters Union and marched with the United Farm Workers in Delano, California, Reuther seemed to be dissatisfied, looking for the ability to challenge the injustices that had made the union movement so vital in the 1930s. He died in a plane crash in 1970. Interstate Highway 696 in the Detroit area is named for Reuther.