List of socialist members of the United States Congress

The following is a list of members of the United States Congress who have declared themselves to be socialists or have been a member of a socialist organization in the United States.

The First Red Scare and Second Red Scare, and McCarthy era, resulted in persecution of socialists, removal of socialists from unions, and weaker socialist electoral outcomes.

There are currently more socialists in Congress than any point in US history, most of whom are Democratic Socialists of America (DSA) members.

Notable progressive but not socialist Congress members

 * Maxwell Frost (1997–, FL's 10th congressional district) is a progressive and the first Generation Z member of Congress. Frost explicitly does not identify as socialist, saying "my family fled that".
 * Ayanna Pressley (1974–, MA's 7th congressional district) is a member of "The Squad". Pressley explicitly does not identify as socialist.
 * Shri Thanedar (1955–, MI's 13th congressional district) is a Democrat and expelled DSA member. Thanedar is not considered a socialist or reflective of the values of the organization.
 * Raúl Grijalva (1948-, AZ-7) is a Democrat and member of the Congressional Progressive Caucus, Blue Collar Caucus and the Justice Democrats. He has been ranked as among the most left leaning members of congress by GovTrack and National journal, and was a member of the Raza Unida Party in his youth, but has not governed as a socialist.
 * George Crockett Jr. (1909–1996, MI's 13th congressional district) was a National Lawyers Guild member who attended the DSA founding conference, but never joined the group itself.
 * Allard K. Lowenstein (1969-1971, NY-5) was aligned with many New Left causes and was supported in his campaigns by DSA members such as Ron Dellums but never identified as a socialist himself.
 * Robert M. La Follette (1855–1925, WI-Sen) aligned himself with Socialist groups but never identified as a Socialist himself.
 * American Labor Party–Democratic Party fusion candidates:
 * Joseph L. Pfeifer (1935–1951)
 * Emanuel Celler (1923–1973)
 * Arthur G. Klein (1941–1945, 1946–1956)
 * Adam Clayton Powell Jr. (1945–1971)
 * Nonpartisan League members:
 * United States senators:
 * Lynn Frazier (1923–1941)
 * William Langer (1941–1959)
 * United States representatives:
 * John Miller Baer (1917–1921)
 * Usher L. Burdick (1949–1959)
 * William Lemke (1933–1941; 1943–1950)
 * Minnesota Farmer–Labor Party members:
 * United States senators:
 * Henrik Shipstead (1923–1941); later became a Republican
 * Magnus Johnson (1923–1925)
 * Elmer Austin Benson (1935–1937)
 * Ernest Lundeen (1937–1940)
 * United States representatives:
 * William Leighton Carss (1919–1921, 1925–1929)
 * Ole J. Kvale (1923–1929)
 * Knud Wefald (1923–1927)
 * Paul John Kvale (1929–1939)
 * Henry M. Arens (1933–1935)
 * Magnus Johnson (1933–1935)
 * Ernest Lundeen (1933–1937); had previously served as a Republican Representative (1915–1917), also served in the Senate
 * Francis Shoemaker (1933–1935)