| Incumbent re-elected. | nowrap | |- ! | Henry Brush | | Democratic-Republican | 1818 | | Incumbent lost re-election.New member elected.Democratic-Republican hold. | nowrap | |- ! | Samuel Herrick | | Democratic-Republican | 1816 | | Incumbent retired.New member elected.Democratic-Republican hold.Winner declined to serve, leading to an October 9, 1821 special election. | nowrap | |- ! | Philemon Beecher | | Federalist | 1816 | | Incumbent lost re-election.New member elected.Democratic-Republican gain. | nowrap | |- ! | John Sloane | | Democratic-Republican | 1818 | Incumbent re-elected. | nowrap | |} Pennsylvania Pennsylvania elected its members October 10, 1820. |- ! rowspan=4 | | Joseph Hemphill | | Federalist | 18001802 1818 | Incumbent re-elected. | rowspan=4 nowrap | |- | Samuel Edwards | | Federalist | 1818 | Incumbent re-elected. |- | Thomas Forrest | | Federalist | 1818 | | Incumbent lost re-election.New member elected.Federalist hold. |- | John Sergeant | | Federalist | 1815 | Incumbent re-elected. |- ! rowspan=2 | | William Darlington | | Democratic-Republican | 18141816 1818 | Incumbent re-elected. | rowspan=2 nowrap | |- | Samuel Gross | | Democratic-Republican | 1818 | Incumbent re-elected. |- ! rowspan=2 | | James M. Wallace | | Democratic-Republican | 1815 | | Incumbent lost re-election.New member elected.Federalist gain. | rowspan=2 nowrap | |- | Jacob Hibshman | | Democratic-Republican | 1818 | | Incumbent lost re-election.New member elected.Federalist gain. |- ! | Jacob Hostetter | | Democratic-Republican | 1818 | | Incumbent lost re-election.New member elected.Democratic-Republican hold. | nowrap | |- ! rowspan=2 | | Andrew Boden | | Democratic-Republican | 1816 | | Incumbent retired.New member elected.Democratic-Republican hold. | rowspan=2 nowrap | |- | David Fullerton | | Democratic-Republican | 1818 | | Incumbent resigned May 15, 1820.New member elected.Democratic-Republican hold.Successor was not a candidate in the same day's election to finish the term.Successor resigned in April 1821, leading to an October 9, 1821 special election. |- ! rowspan=2 | | Samuel Moore | | Democratic-Republican | 1818 | Incumbent re-elected. | rowspan=2 nowrap | |- | Thomas J. Rogers | | Democratic-Republican | 1818 | Incumbent re-elected. |- ! | Joseph Hiester | | Democratic-Republican | 17981804 1814 | | Incumbent retired to run for Governor of Pennsylvania.New member elected.Federalist gain.Incumbent then resigned in December 1820 when elected Governor of Pennsylvania and successor lost the December 10, 1820