# Pennsylvania's 12th congressional district

Pennsylvania's 12th congressional district is located in southwestern Pennsylvania, including Pittsburgh and much of Allegheny County, as well as some of Westmoreland County. Since January 3, 2023, it has been represented by Summer Lee.
Before 2018, the 12th district was located in southwestern Pennsylvania and included all of Beaver County, and parts of Allegheny, Cambria, Lawrence, Somerset, and Westmoreland Counties. The Supreme Court of Pennsylvania redrew this and other state congressional districts in February 2018 after ruling the previous map unconstitutional due to partisan gerrymandering. The new 12th district covers much of the old 10th district. The old 12th district was redrawn to an area north and west of Pittsburgh and renamed the 17th district for the 2018 elections and representation after that.
Before the 2011 round of redistricting, the 12th district was widely considered to be gerrymandered by the Republican-controlled state legislature as a heavily Democratic district. It consisted of all of Greene County, and parts of Allegheny, Armstrong, Cambria, Fayette, Indiana, Somerset, Washington, and Westmoreland Counties.

## Recent election results from statewide races

| Year | Office | Results |
| 2008 | President | Obama 59% – 40% |
| 2008 | Attorney General | Morganelli 51% - 49% |
| 2008 | Auditor General | Wagner 75% - 25% |
| 2010 | Senate | Sestak 57% - 43% |
| 2010 | Governor | Onorato 52% - 48% |
| 2012 | President | Obama 60% - 40% |
| 2012 | Senate | Casey Jr. 63% - 37% |
| 2014 | Governor | Wolf 61% - 39% |
| 2016 | President | Clinton 57% – 40% |
| 2016 | Senate | McGinty 57% – 39% |
| 2016 | Attorney General | Shapiro 61% – 39% |
| 2016 | Treasurer | Torsella 61% – 33% |
| 2016 | Auditor General | DePasquale 64% – 31% |
| 2018 | Senate | Casey Jr. 66% – 32% |
| 2018 | Governor | Wolf 68% – 31% |
| 2020 | President | Biden 59% – 39% |
| 2020 | Attorney General | Shapiro 62% – 34% |
| 2020 | Treasurer | Torsella 58% – 38% |
| 2020 | Auditor General | Ahmad 57% – 39% |
| 2022 | Senate | Fetterman 63% – 35% |
| 2022 | Governor | Shapiro 68% – 30% |
| 2024 | President | Harris 59% – 40% |

## History

After the 2000 census, the Republican-controlled state legislature radically altered the 12th to get more Republicans elected from traditionally heavily Democratic southwestern Pennsylvania. A large chunk of the old 20th district was incorporated into the 12th. In some parts of the western portion of the district, one side of the street is in the 12th, while the other is in the 18th district (the reconfigured 20th). This led to criticism that the 12th was a gerrymander intended to pack as many of southwestern Pennsylvania's heavily Democratic areas as possible into just two districts—the 12th and the Pittsburgh-based 14th.
Located in southwestern Pennsylvania, the 12th district consisted of all of Greene County, and parts of Allegheny, Armstrong, Cambria, Fayette, Indiana, Somerset, Washington, and Westmoreland Counties. A thoroughly unionized district, the 12th was historically among the most Democratic areas of the state. However, the Democrats in this area were not as liberal as their counterparts in Philadelphia and Pittsburgh. Most were somewhat conservative on social issues, particularly abortion and gun control.
The 12th included all of Greene County, a highly rural region that still has a traditionally Democratic influence due to its labor leanings. In Washington county, the city of Washington and eastern portions of the county, a large and Democratic edge suburb of Pittsburgh, was a part of the 12th. Most of the Monongahela Valley region, a very Democratic area once an important steel-making area, was also part of the 12th. However, more rural western Washington County and the suburban northern portion of the county (with towns like McDonald and Canonsburg) then belonged to the 18th. The western portion of Fayette County, including the city of Uniontown, a labor Democratic stronghold, was part of this district. In contrast, the rural mountainous eastern portion was a part of the 9th.
The 12th district continued eastward, including southeastern and northeastern parts of Westmoreland County, including the labor Democratic city of Latrobe, while leaving the suburban western part of the county (with towns such as Murrysville) and the generally left-leaning city of Greensburg in the 18th. The major population base of the district was located just to the east, taking in most of Somerset and Cambria counties. This area, the heart of a sizeable coal-mining region, includes the district's largest city, Johnstown. The 12th also contained a part of Indiana County, mainly the college town of Indiana.
The 12th completed its wrap around the metro Pittsburgh region by ending in the northeastern corner of the city's suburbs, containing middle-class regions such as Lower Burrell and the working-class suburb of New Kensington. A portion of Armstrong County was also included in the district, including several industrial suburbs such as Freeport and Apollo. The district is notable as the only congressional district in the nation that voted for Democratic presidential candidate John Kerry in 2004 but went for Republican John McCain in 2008. This is mainly because, since 2000, southwestern Pennsylvania has gradually become more Republican.

### 2006 election

In the 2006 election, Murtha was re-elected with 61% of the vote. His Republican opponent, Washington County Commissioner Diana Irey, received 39%.

### 2008 election

John Murtha won the 2008 election with 58% of the vote. Murtha was a United States Marine and the first Vietnam War veteran to serve in Congress. He defeated Lt. Col. William T. Russell, an army veteran.

### 2010 special election

Pennsylvania governor Ed Rendell scheduled a special election for May 18, 2010, following the death of Representative John Murtha. On March 8, 2010, the Pennsylvania Democratic Party's Executive Committee nominated Mark Critz, Murtha's former district director. On March 11, a convention of Republicans from the 12th district nominated businessman Tim Burns. The Libertarian Party's candidate was Demo Agoris, who ran for the Pennsylvania House of Representatives in the 48th district as a Libertarian in 2006.
Mark Critz won the election.

### 2010 election

Mark Critz was re-elected in the regularly scheduled 2010 election, again beating Republican Tim Burns (this time with 51% of the vote against 49%).

### 2012 election

Mark Critz ran for re-election to a second full term in the 2012 election but was defeated by Republican challenger Keith Rothfus. Critz garnered 48.5% of the vote to Rothfus' 51.5%. The 12th had absorbed a large chunk of the old 4th district, including Rothfus' home, after the 2010 census, and was significantly more Republican than its predecessor.

### 2019 special election

After Tom Marino's resignation in January 2019, an election was held on May 21 to fill the open seat. Republican Fred Keller defeated 2018 Democratic nominee Mark Friedenberg.

## Counties and municipalities

Allegheny County (46)
    Baldwin, Bethel Park, Braddock, Brentwood, Bridgeville, Chalfant, Clairton, Dravosburg, Duquesne, East McKeesport, East Pittsburgh, Elizabeth Borough, Elizabeth Township, Forward Township, Glassport, Homestead, Jefferson Hills, Liberty, Lincoln, McKeesport, Monroeville, Mount Oliver, Munhall, North Braddock, North Versailles Township, Pitcairn, Pittsburgh, Pleasant Hills, Plum, Port Vue, Rankin, South Park Township, South Versailles Township, Swissvale (part; also 17th), Trafford (shared with Westmoreland County) Turtle Creek, Upper St. Clair Township, Versailles, Wall, West Elizabeth, West Homestead, West Mifflin, Whitaker, Whitehall, White Oak, Wilkins Township, Wilmerding

### Westmoreland County (17)

    Adamsburg, Arona, Export, Hempfield Township (part; also 14th), Irwin, Jeannette, Madison, Manor, Murrysville, North Huntingdon Township, North Irwin, Penn Borough, Penn Township, Sewickley Township, South Huntingdon Township (part; also 14th), Sutersville, Trafford (shared with Allegheny County)

## List of members representing the district

| Representative | Party | Years | Cong ress | Electoral history | Location |
| District established March 4, 1795 ||||||
| Albert Gallatin (Springhill Township) | Democratic-Republican | March 4, 1795 – May 14, 1801 | 4th 5th 6th 7th | Elected in 1794. Re-elected in 1796. Re-elected in 1798. Re-elected in 1800 but declined the seat to become U.S. Secretary of the Treasury. | 1795–1803 [data missing] |
| Vacant | Vacant | May 14, 1801 – December 7, 1801 | 7th | | 1795–1803 [data missing] |
| William Hoge (Washington) | Democratic-Republican | December 7, 1801 – March 3, 1803 | 7th | Elected October 13, 1801, to finish Gallatin's term and seated December 7, 1801. Redistricted to the 10th district. | 1795–1803 [data missing] |
| District dissolved March 3, 1803 ||||||
| District re-established March 4, 1813 ||||||
| Aaron Lyle (West Middletown) | Democratic-Republican | March 4, 1813 – March 3, 1817 | 13th 14th | Redistricted from the 10th district and re-elected in 1812. Re-elected in 1814. Retired. | 1813–1823 [data missing] |
| Thomas Patterson (West Middletown) | Democratic-Republican | March 4, 1817 – March 3, 1823 | 15th 16th 17th | Elected in 1816. Re-elected in 1818. Re-elected in 1820. Redistricted to the 15th district. | 1813–1823 [data missing] |
| John Brown (Lewistown) | Democratic-Republican | March 4, 1823 – March 3, 1825 | 18th | Redistricted from the 9th district and re-elected in 1822. Lost re-election. | 1823–1833 [data missing] |
| John Mitchell (Bellefonte) | Jacksonian | March 4, 1825 – March 3, 1829 | 19th 20th | Elected in 1824. Re-elected in 1826. Retired. | 1823–1833 [data missing] |
| John Scott (Alexandria) | Jacksonian | March 4, 1829 – March 3, 1831 | 21st | Elected in 1828. Lost re-election. | 1823–1833 [data missing] |
| Robert Allison (Huntingdon) | Anti-Masonic | March 4, 1831 – March 3, 1833 | 22nd | Elected in 1830. Retired. | 1823–1833 [data missing] |
| George Chambers (Chambersburg) | Anti-Masonic | March 4, 1833 – March 3, 1837 | 23rd 24th | Elected in 1832. Re-elected in 1834. [data missing] | 1833–1843 [data missing] |
| Daniel Sheffer (York) | Democratic | March 4, 1837 – March 3, 1839 | 25th | Elected in 1836. Lost re-election. | 1833–1843 [data missing] |
| James Cooper (Gettysburg) | Whig | March 4, 1839 – March 3, 1843 | 26th 27th | Elected in 1838. Re-elected in 1840. [data missing] | 1833–1843 [data missing] |
| Almon H. Read (Montrose) | Democratic | March 4, 1843 – June 3, 1844 | 28th | Redistricted from the 17th district and re-elected in 1842. Died. | 1843–1853 [data missing] |
| Vacant | Vacant | June 3, 1844 – December 2, 1844 | 28th | | 1843–1853 [data missing] |
| George Fuller (Montrose) | Democratic | December 2, 1844 – March 3, 1845 | 28th | Elected to finish Read's term. [data missing] | 1843–1853 [data missing] |
| David Wilmot (Towanda) | Democratic | March 4, 1845 – March 3, 1851 | 29th 30th 31st | Elected in 1844. Re-elected in 1846. Re-elected in 1848. Retired. | 1843–1853 [data missing] |
| Galusha A. Grow (Glenwood) | Democratic | March 4, 1851 – March 3, 1853 | 32nd | Elected in 1850. Redistricted to the 14th district. | 1843–1853 [data missing] |
| Hendrick B. Wright (Wilkes-Barre) | Democratic | March 4, 1853 – March 3, 1855 | 33rd | Elected in 1852. Lost re-election. | 1853–1863 [data missing] |
| Henry M. Fuller (Wilkes-Barre) | Opposition | March 4, 1855 – March 3, 1857 | 34th | Elected in 1854. Retired. | 1853–1863 [data missing] |
| John G. Montgomery (Danville) | Democratic | March 4, 1857 – April 24, 1857 | 35th | Elected in 1856. Died. | 1853–1863 [data missing] |
| Vacant | Vacant | April 24, 1857 – December 7, 1857 | 35th | | 1853–1863 [data missing] |
| Paul Leidy (Danville) | Democratic | December 7, 1857 – March 3, 1859 | 35th | Elected to finish Montgomery's term. [data missing] | 1853–1863 [data missing] |
| George W. Scranton (Scranton) | Republican | March 4, 1859 – March 24, 1861 | 36th 37th | Elected in 1858. Re-elected in 1860. Died. | 1853–1863 [data missing] |
| Vacant | Vacant | March 24, 1861 – July 4, 1861 | 37th | | 1853–1863 [data missing] |
| Hendrick B. Wright (Wilkes-Barre) | Democratic | July 4, 1861 – March 3, 1863 | 37th | Elected to finish Scranton's term. [data missing] | 1853–1863 [data missing] |
| Charles Denison (Wilkes-Barre) | Democratic | March 4, 1863 – June 27, 1867 | 38th 39th 40th | Elected in 1862. Re-elected in 1864. Re-elected in 1866. Died. | 1863–1873 [data missing] |
| Vacant | Vacant | June 27, 1867 – November 21, 1867 | 40th | | 1863–1873 [data missing] |
| George W. Woodward (Wilkes-Barre) | Democratic | November 21, 1867 – March 3, 1871 | 40th 41st | Elected to finish Denison's term. Re-elected in 1868. Retired. | 1863–1873 [data missing] |
| Lazarus D. Shoemaker (Wilkes-Barre) | Republican | March 4, 1871 – March 3, 1875 | 42nd 43rd | Elected in 1870. Re-elected in 1872. Retired. | 1863–1873 [data missing] |
| Lazarus D. Shoemaker (Wilkes-Barre) | Republican | March 4, 1871 – March 3, 1875 | 42nd 43rd | Elected in 1870. Re-elected in 1872. Retired. | 1873–1883 [data missing] |
| Winthrop W. Ketcham (Wilkes-Barre) | Republican | March 4, 1875 – July 19, 1876 | 44th | Elected in 1874. Resigned to become U.S. District Judge | 1873–1883 [data missing] |
| Vacant | Vacant | July 19, 1876 – November 7, 1876 | 44th | | 1873–1883 [data missing] |
| William H. Stanton (Scranton) | Democratic | November 7, 1876 – March 3, 1877 | 44th | Elected to finish Ketcham's term. Retired. | 1873–1883 [data missing] |
| Hendrick B. Wright (Wilkes-Barre) | Democratic | March 4, 1877 – March 3, 1879 | 45th 46th | Elected in 1876. Re-elected in 1878. Lost re-election. | 1873–1883 [data missing] |
| Hendrick B. Wright (Wilkes-Barre) | Greenback | March 4, 1879 – March 3, 1881 | 45th 46th | Elected in 1876. Re-elected in 1878. Lost re-election. | 1873–1883 [data missing] |
| Joseph A. Scranton (Scranton) | Republican | March 4, 1881 – March 3, 1883 | 47th | Elected in 1880. Lost re-election. | 1873–1883 [data missing] |
| Daniel W. Connolly (Scranton) | Democratic | March 4, 1883 – March 3, 1885 | 48th | Elected in 1882. Lost re-election. | 1883–1893 [data missing] |
| Joseph A. Scranton (Scranton) | Republican | March 4, 1885 – March 3, 1887 | 49th | Elected in 1884. Lost re-election. | 1883–1893 [data missing] |
| John Lynch (Wilkes-Barre) | Democratic | March 4, 1887 – March 3, 1889 | 50th | Elected in 1886. Lost re-election. | 1883–1893 [data missing] |
| Edwin S. Osborne (Wilkes-Barre) | Republican | March 4, 1889 – March 3, 1891 | 51st | Redistricted from the at-large district and re-elected in 1888. Retired. | 1883–1893 [data missing] |
| George W. Shonk (Plymouth) | Republican | March 4, 1891 – March 3, 1893 | 52nd | Elected in 1890. Retired. | 1883–1893 [data missing] |
| William H. Hines (Wilkes-Barre) | Democratic | March 4, 1893 – March 3, 1895 | 53rd | Elected in 1892. Lost re-election. | 1893–1903 [data missing] |
| John Leisenring (Upper Lehigh) | Republican | March 4, 1895 – March 3, 1897 | 54th | Elected in 1894. Retired. | 1893–1903 [data missing] |
| Morgan B. Williams (Wilkes-Barre) | Republican | March 4, 1897 – March 3, 1899 | 55th | Elected in 1896. Lost re-election. | 1893–1903 [data missing] |
| Stanley W. Davenport (Plymouth) | Democratic | March 4, 1899 – March 3, 1901 | 56th | Elected in 1898. Lost renomination. | 1893–1903 [data missing] |
| Henry W. Palmer (Wilkes-Barre) | Republican | March 4, 1901 – March 3, 1903 | 57th | Elected in 1900. Redistricted to the 11th district. | 1893–1903 [data missing] |
| George R. Patterson (Ashland) | Republican | March 4, 1903 – March 21, 1906 | 58th 59th | Elected in 1902. Re-elected in 1904. Died. | 1903–1913 [data missing] |
| Vacant | Vacant | January 21, 1906 – November 6, 1906 | 59th | | 1903–1913 [data missing] |
| Charles N. Brumm (Minersville) | Republican | November 6, 1906 – January 4, 1909 | 59th 60th | Elected to finish Patterson's term. Re-elected in 1906. Retired to run for judge of the court of common pleas of Schuylkill County, Pennsylvania, and then resigned once elected. | 1903–1913 [data missing] |
| Vacant | Vacant | January 4, 1909 – March 3, 1909 | 60th | | 1903–1913 [data missing] |
| Alfred B. Garner (Ashland) | Republican | March 4, 1909 – March 3, 1911 | 61st | Elected in 1908. Lost renomination. | 1903–1913 [data missing] |
| Robert E. Lee (Pottsville) | Democratic | March 4, 1911 – March 3, 1915 | 62nd 63rd | Elected in 1910. Re-elected in 1912. Lost re-election. | 1903–1913 [data missing] |
| Robert E. Lee (Pottsville) | Democratic | March 4, 1911 – March 3, 1915 | 62nd 63rd | Elected in 1910. Re-elected in 1912. Lost re-election. | 1913–1933 [data missing] |
| Robert D. Heaton (Ashland) | Republican | March 4, 1915 – March 3, 1919 | 64th 65th | Elected in 1914. Re-elected in 1916. Retired. | 1913–1933 [data missing] |
| John Reber (Pottsville) | Republican | March 4, 1919 – March 3, 1923 | 66th 67th | Elected in 1918. Re-elected in 1920. Retired. | 1913–1933 [data missing] |
| John J. Casey (Wilkes-Barre) | Democratic | March 4, 1923 – March 3, 1925 | 68th | Elected in 1922. Lost re-election. | 1913–1933 [data missing] |
| Edmund N. Carpenter (Wilkes-Barre) | Republican | March 4, 1925 – March 3, 1927 | 69th | Elected in 1924. Lost re-election. | 1913–1933 [data missing] |
| John J. Casey (Wilkes-Barre) | Democratic | March 4, 1927 – May 5, 1929 | 70th 71st | Elected in 1926. Re-elected in 1928. Died. | 1913–1933 [data missing] |
| Vacant | Vacant | May 5, 1929 – June 4, 1929 | 71st | | 1913–1933 [data missing] |
| C. Murray Turpin (Kingston) | Republican | June 4, 1929 – January 3, 1937 | 71st 72nd 73rd 74th | Elected to finish Casey's term. Re-elected in 1930. Re-elected in 1932. Re-elected in 1934. Lost re-election. | 1913–1933 [data missing] |
| C. Murray Turpin (Kingston) | Republican | June 4, 1929 – January 3, 1937 | 71st 72nd 73rd 74th | Elected to finish Casey's term. Re-elected in 1930. Re-elected in 1932. Re-elected in 1934. Lost re-election. | 1933–1943 [data missing] |
| J. Harold Flannery (Pittston) | Democratic | January 3, 1937 – January 3, 1942 | 75th 76th 77th | Elected in 1936. Re-elected in 1938. Re-elected in 1940. Resigned to become judge of the common pleas court of Luzerne County, Pennsylvania. | 1933–1943 [data missing] |
| Vacant | Vacant | January 3, 1942 – May 19, 1942 | 77th | | 1933–1943 [data missing] |
| Thomas B. Miller (Plymouth) | Republican | May 19, 1942 – January 3, 1945 | 77th 78th | Elected to finish Flannery's term. Re-elected later in 1942. Lost re-election. | 1933–1943 [data missing] |
| Thomas B. Miller (Plymouth) | Republican | May 19, 1942 – January 3, 1945 | 77th 78th | Elected to finish Flannery's term. Re-elected later in 1942. Lost re-election. | 1943–1953 [data missing] |
| Ivor D. Fenton (Mahanoy City) | Republican | January 3, 1945 – January 3, 1963 | 79th 80th 81st 82nd 83rd 84th 85th 86th 87th | Redistricted from the 13th district and re-elected in 1944. Re-elected in 1946. Re-elected in 1948. Re-elected in 1950. Re-elected in 1952. Re-elected in 1954. Re-elected in 1956. Re-elected in 1958. Re-elected in 1960. Lost re-election. | 1943–1953 [data missing] |
| Ivor D. Fenton (Mahanoy City) | Republican | January 3, 1945 – January 3, 1963 | 79th 80th 81st 82nd 83rd 84th 85th 86th 87th | Redistricted from the 13th district and re-elected in 1944. Re-elected in 1946. Re-elected in 1948. Re-elected in 1950. Re-elected in 1952. Re-elected in 1954. Re-elected in 1956. Re-elected in 1958. Re-elected in 1960. Lost re-election. | 1953–1963 [data missing] |
| J. Irving Whalley (Windber) | Republican | January 3, 1963 – January 3, 1973 | 88th 89th 90th 91st 92nd | Redistricted from the 18th district and re-elected in 1962. Re-elected in 1964. Re-elected in 1966. Re-elected in 1968. Re-elected in 1970. Retired. | 1963–1973 [data missing] |
| John P. Saylor (Johnstown) | Republican | January 3, 1973 – October 28, 1973 | 93rd | Redistricted from the 22nd district and re-elected in 1972. Died. | 1973–1983 [data missing] |
| Vacant | Vacant | October 28, 1973 – February 5, 1974 | 93rd | | 1973–1983 [data missing] |
| John Murtha (Johnstown) | Democratic | February 5, 1974 – February 8, 2010 | 93rd 94th 95th 96th 97th 98th 99th 100th 101st 102nd 103rd 104th 105th 106th 107th 108th 109th 110th 111th | Elected to finish Saylor's term. Re-elected later in 1974. Re-elected in 1976. Re-elected in 1978. Re-elected in 1980. Re-elected in 1982. Re-elected in 1984. Re-elected in 1986. Re-elected in 1988. Re-elected in 1990. Re-elected in 1992. Re-elected in 1994. Re-elected in 1996. Re-elected in 1998. Re-elected in 2000. Re-elected in 2002. Re-elected in 2004. Re-elected in 2006. Re-elected in 2008. Died. | 1973–1983 [data missing] |
| John Murtha (Johnstown) | Democratic | February 5, 1974 – February 8, 2010 | 93rd 94th 95th 96th 97th 98th 99th 100th 101st 102nd 103rd 104th 105th 106th 107th 108th 109th 110th 111th | Elected to finish Saylor's term. Re-elected later in 1974. Re-elected in 1976. Re-elected in 1978. Re-elected in 1980. Re-elected in 1982. Re-elected in 1984. Re-elected in 1986. Re-elected in 1988. Re-elected in 1990. Re-elected in 1992. Re-elected in 1994. Re-elected in 1996. Re-elected in 1998. Re-elected in 2000. Re-elected in 2002. Re-elected in 2004. Re-elected in 2006. Re-elected in 2008. Died. | 1983–1993 [data missing] |
| John Murtha (Johnstown) | Democratic | February 5, 1974 – February 8, 2010 | 93rd 94th 95th 96th 97th 98th 99th 100th 101st 102nd 103rd 104th 105th 106th 107th 108th 109th 110th 111th | Elected to finish Saylor's term. Re-elected later in 1974. Re-elected in 1976. Re-elected in 1978. Re-elected in 1980. Re-elected in 1982. Re-elected in 1984. Re-elected in 1986. Re-elected in 1988. Re-elected in 1990. Re-elected in 1992. Re-elected in 1994. Re-elected in 1996. Re-elected in 1998. Re-elected in 2000. Re-elected in 2002. Re-elected in 2004. Re-elected in 2006. Re-elected in 2008. Died. | 1993–2003 [data missing] |
| John Murtha (Johnstown) | Democratic | February 5, 1974 – February 8, 2010 | 93rd 94th 95th 96th 97th 98th 99th 100th 101st 102nd 103rd 104th 105th 106th 107th 108th 109th 110th 111th | Elected to finish Saylor's term. Re-elected later in 1974. Re-elected in 1976. Re-elected in 1978. Re-elected in 1980. Re-elected in 1982. Re-elected in 1984. Re-elected in 1986. Re-elected in 1988. Re-elected in 1990. Re-elected in 1992. Re-elected in 1994. Re-elected in 1996. Re-elected in 1998. Re-elected in 2000. Re-elected in 2002. Re-elected in 2004. Re-elected in 2006. Re-elected in 2008. Died. | 2003–2013 |
| Vacant | Vacant | February 8, 2010 – May 18, 2010 | 111th | | 2003–2013 |
| Mark Critz (Johnstown) | Democratic | May 18, 2010 – January 3, 2013 | 111th 112th | Elected to finish Murtha's term. Re-elected later in 2010. Lost re-election. | 2003–2013 |
| Keith Rothfus (Sewickley) | Republican | January 3, 2013 – January 3, 2019 | 113th 114th 115th | Elected in 2012. Re-elected in 2014. Re-elected in 2016. Redistricted to the 17th district and lost re-election. | 2013–2019 |
| Tom Marino (Williamsport) | Republican | January 3, 2019 – January 23, 2019 | 116th | Redistricted from the 10th district and re-elected in 2018. Resigned. | 2019–2023 |
| Vacant | Vacant | January 23, 2019 – May 21, 2019 | 116th | | 2019–2023 |
| Fred Keller (Middleburg) | Republican | May 21, 2019 – January 3, 2023 | 116th 117th | Elected to finish Marino's term. Re-elected in 2020. Redistricted to the 9th district and retired at the end of term. | 2019–2023 |
| Summer Lee (Swissvale) | Democratic | January 3, 2023 – present | 118th 119th | Elected in 2022. Re-elected in 2024. | 2023– |

## Recent election results
### 2012

Pennsylvania's 12th congressional district, 2012 :
| Party | Party | Candidate | Votes | % |
| | Republican | Keith Rothfus | 175,352 | 51.7 |
| | Democratic | Mark Critz (incumbent) | 163,589 | 48.3 |
| Total votes | Total votes | Total votes | 338,941 | 100.0 |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

### 2014

Pennsylvania's 12th congressional district, 2014 :
| Party | Party | Candidate | Votes | % |
| | Republican | Keith Rothfus (incumbent) | 127,993 | 59.3 |
| | Democratic | Erin McClelland | 87,928 | 40.7 |
| Total votes | Total votes | Total votes | 215,921 | 100.0 |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2016

Pennsylvania's 12th congressional district, 2016 :
| Party | Party | Candidate | Votes | % |
| | Republican | Keith Rothfus (incumbent) | 221,851 | 61.8 |
| | Democratic | Erin Mcclelland | 137,353 | 38.2 |
| Total votes | Total votes | Total votes | 359,204 | 100.0 |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2018

Pennsylvania's 12th congressional district, 2018 :
| Party | Party | Candidate | Votes | % |
| | Republican | Tom Marino (incumbent) | 161,047 | 66.0 |
| | Democratic | Marc Friedenberg | 82,825 | 34.0 |
| Total votes | Total votes | Total votes | 243,872 | 100.0 |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2019 special election

Pennsylvania's 12th congressional district special election, 2019 :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Fred Keller | 90,000 | 68.08% | +2.04% |
| | Democratic | Marc Friedenberg | 42,195 | 31.92% | −2.04% |
| Total votes | Total votes | Total votes | '132,195' | '100.0%' | N/A |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |

### 2020

Pennsylvania's 12th congressional district, 2020 :
| Party | Party | Candidate | Votes | % |
| | Republican | Fred Keller (incumbent) | 241,035 | 70.8 |
| | Democratic | Lee Griffin | 99,199 | 29.2 |
| Total votes | Total votes | Total votes | 340,234 | 100.0 |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2022

Pennsylvania's 12th congressional district, 2022 :
| Party | Party | Candidate | Votes | % |
| | Democratic | Summer Lee | 184,674 | 56.2 |
| | Republican | Mike Doyle | 143,946 | 43.8 |
| Total votes | Total votes | Total votes | 328,620 | 100.0 |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |