Pennsylvania's 31st congressional district was one of Pennsylvania's districts of the United States House of Representatives. It existed from 1903 to 1953.

Created in 1903, the district served portions of the city of Pittsburgh. The district later expanded to serve portions of Allegheny County

During the 58th Congress, the district served Pittsburgh Wards 1-19 and Ward 23.

During the 81st Congress, the district served Wards 19, 20, 28, 29, 30, and 32 in Pittsburgh and the following portions of Allegheny County.

• Boroughs served by the 31st District
  • Brentwood
  • Bridgeville
  • Carnegie
  • Castle Shannon
  • Coraopolis
  • Crafton
  • Dormont
  • Green Tree
  • Heidelberg
  • Ingram
  • McDonald
    (5th election district)
  • McKees Rocks
  • Mount Oliver
  • Oakdale
  • Rosslyn Farms
  • Thornburg
• Townships served by the 31st District
  • Baldwin
  • Bethel
  • Collier
  • Crescent
  • Findlay
  • Kennedy
  • Moon
  • Mount Lebanon
  • Neville
  • North Fayette
  • Robinson
  • Scott
  • South Fayette
  • Stowe
  • Upper St. Clair

• 188,099 (1900 census)
• 295,063 (1940 census)

This district was created in 1903, then eliminated in 1953.

Representative	Party	Years	Cong ress	Electoral history
District established March 4, 1903
Henry K. Porter (Pittsburgh)	Independent Republican	March 4, 1903 – March 3, 1905	58th	Elected in 1902. Lost re-nomination.
James F. Burke (Pittsburgh)	Republican	March 4, 1905 – March 3, 1915	59th 60th 61st 62nd 63rd	Elected in 1904. Re-elected in 1906. Re-elected in 1908. Re-elected in 1910. Re-elected in 1912. Retired.
John M. Morin (Pittsburgh)	Republican	March 4, 1915 – March 3, 1923	64th 65th 66th 67th	Redistricted from the At-large district and re-elected in 1914. Re-elected in 1916. Re-elected in 1918 Re-elected in 1920. Redistricted to the 34th district.
Adam M. Wyant (Greensburg)	Republican	March 4, 1923 – March 3, 1933	68th 69th 70th 71st 72nd	Redistricted from the 22nd district and re-elected in 1922. Re-elected in 1924. Re-elected in 1926. Re-elected in 1928. Re-elected in 1930. Lost re-election.
M. Clyde Kelly (Edgewood)	Republican	March 3, 1933 – January 3, 1935	73rd	Redistricted from the 33rd district and re-elected in 1932. Lost re-election.
James L. Quinn (Braddock)	Democratic	January 3, 1935 – January 3, 1939	74th 75th	Elected in 1934. Re-elected in 1936. Lost re-election.
John McDowell (Wikinsburg)	Republican	January 3, 1939 – January 3, 1941	76th	Elected in 1938. Lost re-election.
Samuel A. Weiss (Glassport)	Democratic	January 3, 1941 – January 3, 1943	77th	Elected in 1940. Redistricted to the 33rd district.
Herman P. Eberharter (Pittsburgh)	Democratic	January 3, 1943 – January 3, 1945	78th	Redistricted from the 32nd district and re-elected in 1942. Redistricted to the 32nd district.
James G. Fulton (Pittsburgh)	Republican	January 3, 1945 – January 3, 1953	79th 80th 81st 82nd	Elected in 1944. Re-elected in 1946. Re-elected in 1948. Re-elected in 1950. Redistricted to the 27th district.
District dissolved January 3, 1953

• Martis, Kenneth C. (1989). The Historical Atlas of Political Parties in the United States Congress. New York: Macmillan Publishing Company.
• Martis, Kenneth C. (1982). The Historical Atlas of United States Congressional Districts. New York: Macmillan Publishing Company.
• Congressional Biographical Directory of the United States 1774–present

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