South Carolina ratified the United States Constitution on May 23, 1788. Its Senate seats were declared vacant in July 1861 owing to its secession from the Union. They were again filled from July 1868. The state's current U.S. senators are Tim Scott and Darline Graham. Darline's Senate seat used to belong to her brother, Lindsey Graham, who died in office after serving for 23 years. Strom Thurmond was the state's longest-serving senator (1954–1956, 1956–2003). South Carolina is one of eighteen states alongside California, Colorado, Delaware, Georgia, Hawaii, Idaho, Louisiana, Maine, Massachusetts, Minnesota, Missouri, Nevada, Oklahoma, Pennsylvania, South Dakota, Utah, and West Virginia, to have a younger senior senator and an older junior senator.
List of senators
|- style="height:2em" ! rowspan=4 | 1 | rowspan=4 align=left | Pierce Butler | | Pro-Admin. | rowspan=4 nowrap | Mar 4, 1789 –Oct 25, 1796 | rowspan=2 | Elected in 1789. | rowspan=2 | 1 | | rowspan=3 | 1 | rowspan=3 | Elected in 1789.Retired. | rowspan=3 nowrap | Mar 4, 1789 –Mar 3, 1795 | rowspan=3 | Pro-Admin. | rowspan=3 align=right | Ralph Izard ! rowspan=3 | 1
|- style="height:2em" | rowspan=2 | Anti-Admin.
|- style="height:2em" | rowspan=2 | Re-elected in 1793.Resigned. | rowspan=6 | 2
|- style="height:2em" | | Democratic-Republican | | rowspan=6 | 2 | rowspan=6 | Elected in 1794 or 1795.Lost re-election. | rowspan=6 nowrap | Mar 4, 1795 –Mar 3, 1801 | rowspan=6 | Federalist | rowspan=6 align=right | Jacob Read ! rowspan=6 | 2
|- style="height:2em" | colspan=3 | Vacant | nowrap | Oct 25, 1796 –Dec 8, 1796
|- style="height:2em" ! rowspan=2 | 2 | rowspan=2 align=left | John Hunter | rowspan=2 | Democratic-Republican | rowspan=2 nowrap | Dec 8, 1796 –Nov 26, 1798 | rowspan=2 | Elected to finish Butler's term.Resigned.
|- style="height:2em" | rowspan=2
|- style="height:2em" ! rowspan=3 | 3 | rowspan=3 align=left | Charles Pinckney | rowspan=3 | Democratic-Republican | rowspan=3 nowrap | Dec 6, 1798 –Jun 6, 1801 | Elected to finish Butler's term.
|- style="height:2em" | rowspan=2 | Re-elected in 1799.Resigned to become U.S. Minister to Spain. | rowspan=9 | 3
|- style="height:2em" | rowspan=5 | rowspan=9 | 3 | rowspan=3 | Elected in 1800.Died. | rowspan=3 nowrap | Mar 4, 1801 –Oct 26, 1802 | rowspan=3 | Democratic-Republican | rowspan=3 align=right | John E. Colhoun ! rowspan=3 | 3
|- style="height:2em" | colspan=3 | Vacant | nowrap | Jun 6, 1801 –Dec 15, 1801
|- style="height:2em" ! rowspan=9 | 4 | rowspan=9 align=left | Thomas Sumter | rowspan=9 | Democratic-Republican | rowspan=9 nowrap | Dec 15, 1801 –Dec 16, 1810 | rowspan=6 | Elected in 1801 to finish Pinckney's term.
|- style="height:2em"
| nowrap | Oct 26, 1802 –Nov 4, 1802 | colspan=3 | Vacant
|- style="height:2em" | rowspan=2 | Elected to finish Colhoun's term.Resigned. | rowspan=2 nowrap | Nov 4, 1802 –Nov 21, 1804 | rowspan=2 | Democratic-Republican | rowspan=2 align=right | Pierce Butler ! rowspan=2 | 4
|- style="height:2em"
|- style="height:2em"
| nowrap | Nov 21, 1804 –Dec 6, 1804 | colspan=3 | Vacant
|- style="height:2em" | rowspan=2 | Elected to finish Colhoun's term. | rowspan=16 nowrap | Dec 6, 1804 –Feb 26, 1826 | rowspan=15 | Democratic-Republican | rowspan=16 align=right | John Gaillard ! rowspan=16 | 5
|- style="height:2em" | rowspan=3 | Re-elected in 1804.Resigned. | rowspan=5 | 4
|- style="height:2em" | | rowspan=5 | 4 | rowspan=5 | Re-elected in 1806.
|- style="height:2em"
|- style="height:2em" | colspan=3 | Vacant | nowrap | Dec 16, 1810 –Dec 31, 1810
|- style="height:2em" ! rowspan=4 | 5 | rowspan=4 align=left | John Taylor | rowspan=4 | Democratic-Republican | rowspan=4 nowrap | Dec 31, 1810 –Nov 1816 | Elected to finish Sumter's term.
|- style="height:2em" | rowspan=3 | Re-elected in 1810.Resigned. | rowspan=5 | 5
|- style="height:2em" | | rowspan=5 | 5 | rowspan=5 | Re-elected in 1812.
|- style="height:2em"
|- style="height:2em" | colspan=3 | Vacant | nowrap | Nov 1816 –Dec 4, 1816
|- style="height:2em" ! rowspan=4 | 6 | rowspan=4 align=left | William Smith | rowspan=4 | Democratic-Republican | rowspan=4 nowrap | Dec 4, 1816 –Mar 3, 1823 | Elected to finish Taylor's term.
|- style="height:2em" | rowspan=3 | Re-elected in 1816.Lost re-election. | rowspan=3 | 6
|- style="height:2em" | | rowspan=3 | 6 | rowspan=3 | Re-elected in 1818.
|- style="height:2em"
|- style="height:2em" ! rowspan=8 | 7 | rowspan=8 align=left | Robert Y. Hayne | | Democratic-Republican | rowspan=8 nowrap | Mar 4, 1823 –Dec 13, 1832 | rowspan=6 | Elected in 1822. | rowspan=6 | 7
|- style="height:2em" | rowspan=6 | Jacksonian | rowspan=4 | rowspan=6 | 7 | Re-elected in 1824.Died. | | Jacksonian
|- style="height:2em"
| nowrap | Feb 26, 1826 –Mar 8, 1826 | colspan=3 | Vacant
|- style="height:2em" | Appointed to continue Gaillard's term. | nowrap | Mar 8, 1826 –Nov 29, 1826 | | Jacksonian | align=right | William Harper ! 6
|- style="height:2em" | rowspan=3 | Elected to finish Gaillard's term.Lost re-election. | rowspan=3 nowrap | Nov 29, 1826 –Mar 3, 1831 | rowspan=3 | Jacksonian | rowspan=3 align=right | William Smith ! rowspan=3 | 7
|- style="height:2em"
|- style="height:2em" | rowspan=2 | Re-elected in 1828.Resigned to become South Carolina Governor. | rowspan=6 | 8
|- style="height:2em" | | Nullifier | | rowspan=6 | 8 | rowspan=3 | Elected in 1830.Resigned due to ill health. | rowspan=3 nowrap | Mar 4, 1831 –Mar 3, 1833 | rowspan=3 | Nullifier | rowspan=3 align=right | Stephen Decatur Miller ! rowspan=3 | 8
|- style="height:2em" | colspan=3 | Vacant | nowrap | Dec 13, 1832 –Dec 29, 1832
|- style="height:2em" ! rowspan=9 | 8 | rowspan=9 align=left | John C. Calhoun | rowspan=4 | Nullifier | rowspan=9 nowrap | Dec 29, 1832 –Mar 3, 1843 | rowspan=3 | Elected to finish Hayne's term.
|- style="height:2em" | rowspan=2
| nowrap | Mar 3, 1833 –Nov 26, 1833 | colspan=3 | Vacant
|- style="height:2em" | rowspan=2 | Elected to finish Miller's term. | rowspan=5 nowrap | Nov 26, 1833 –Nov 29, 1842 | rowspan=2 | Nullifier | rowspan=5 align=right | William C. Preston ! rowspan=5 | 9
|- style="height:2em" | rowspan=3 | Re-elected in 1834. | rowspan=3 | 9
|- style="height:2em" | rowspan=5 | Democratic | | rowspan=5 | 9 | rowspan=3 | Re-elected in 1837.Resigned. | rowspan=3 | Whig
|- style="height:2em"
|- style="height:2em" | rowspan=3 | Re-elected in 1840.Resigned. | rowspan=8 | 10
|- style="height:2em"
| nowrap | Nov 29, 1842 –Dec 23, 1842 | colspan=3 | Vacant
|- style="height:2em" | Elected to finish Preston's term. | rowspan=4 nowrap | Dec 23, 1842 –Aug 17, 1846 | rowspan=4 | Democratic | rowspan=4 align=right | George McDuffie ! rowspan=4 | 10
|- style="height:2em" ! 9 | align=left | Daniel Elliott Huger | | Democratic | nowrap | Mar 4, 1843 –Mar 3, 1845 | Elected to finish Calhoun's term.Resigned. | | rowspan=6 | 10 | rowspan=3 | Re-elected in 1842 or 1843.
|- style="height:2em" | colspan=3 | Vacant | nowrap | Mar 3, 1845 –Nov 26, 1845
| rowspan=4
|- style="height:2em" ! rowspan=5 | 10 | rowspan=5 align=left | John C. Calhoun | rowspan=5 | Democratic | rowspan=5 nowrap | Nov 26, 1845 –Mar 31, 1850 | rowspan=3 | Re-elected to finish his own term.
|- style="height:2em"
| nowrap | Aug 17, 1846 –Dec 4, 1846 | colspan=3 | Vacant
|- style="height:2em" | rowspan=2 | Appointed to continue McDuffie's term.Elected to finish McDuffie's term. | rowspan=15 nowrap | Dec 4, 1846 –May 25, 1857 | rowspan=15 | Democratic | rowspan=15 align=right | Andrew Butler ! rowspan=15 | 11
|- style="height:2em" | rowspan=2 | Re-elected in 1846.Died. | rowspan=11 | 11
|- style="height:2em" | rowspan=7 | rowspan=11 | 11 | rowspan=11 | Re-elected in 1848.
|- style="height:2em" | colspan=3 | Vacant | nowrap | Mar 31, 1850 –Apr 11, 1850
|- style="height:2em" ! 11 | align=left | Franklin H. Elmore | | Democratic | nowrap | Apr 11, 1850 –May 29, 1850 | Appointed to continue Calhoun's term.Died.
|- style="height:2em" | colspan=3 | Vacant | nowrap | May 29, 1850 –Jun 4, 1850
|- style="height:2em" ! 12 | align=left | Robert W. Barnwell | | Democratic | nowrap | Jun 4, 1850 –Dec 8, 1850 | Appointed to continue Calhoun's term.Retired when his successor was elected.
|- style="height:2em" | colspan=3 | Vacant | nowrap | Dec 8, 1850 –Dec 18, 1850
|- style="height:2em" ! rowspan=2 | 13 | rowspan=2 align=left | Robert Rhett | rowspan=2 | Democratic | rowspan=2 nowrap | Dec 18, 1850 –May 7, 1852 | rowspan=2 | Elected to finish Calhoun's term.Resigned.
|- style="height:2em"
|- style="height:2em" | colspan=3 | Vacant | nowrap | May 7, 1852 –May 10, 1852
|- style="height:2em" ! 14 | align=left | William F. De Saussure | | Democratic | nowrap | May 10, 1852 –Mar 3, 1853 | Appointed to continue Calhoun's term.Elected Nov 29, 1852 to finish Calhoun's term.
|- style="height:2em" ! rowspan=5 | 15 | rowspan=5 align=left | Josiah Evans | rowspan=5 | Democratic | rowspan=5 nowrap | Mar 4, 1853 –May 6, 1858 | rowspan=5 | Elected in 1852 or 1853.Died. | rowspan=8 | 12
|- style="height:2em" | | rowspan=10 | 12 | rowspan=2 | Re-elected in 1854.Died.
|- style="height:2em" | rowspan=6
|- style="height:2em"
| nowrap | May 25, 1857 –Dec 7, 1857 | colspan=3 | Vacant
|- style="height:2em" | rowspan=6 | Elected to finish Butler's term.Withdrew. | rowspan=6 nowrap | Dec 7, 1857 –Nov 11, 1860 | rowspan=6 | Democratic | rowspan=6 align=right | James H. Hammond ! rowspan=6 | 12
|- style="height:2em" | colspan=3 | Vacant | nowrap | May 6, 1858 –May 11, 1858
|- style="height:2em" ! 16 | align=left | Arthur P. Hayne | | Democratic | nowrap | May 11, 1858 –Dec 2, 1858 | Appointed to continue Evans' term.Retired when his successor was elected.
|- style="height:2em" ! rowspan=2 | 17 | rowspan=2 align=left | James Chesnut Jr. | rowspan=2 | Democratic | rowspan=2 nowrap | Dec 3, 1858 –Nov 10, 1860 | Elected to finish Evans' term.
|- style="height:2em" | Re-elected in 1858.Withdrew and was later expelled for his support of the Confederacy. | rowspan=5 | 13
|- style="height:2em" | rowspan=6 colspan=3 | Vacant | rowspan=6 nowrap | Nov 10, 1860 –Jul 15, 1868 | rowspan=6 | Civil War and Reconstruction.
|- style="height:2em" | rowspan=6 | Civil War and Reconstruction. | rowspan=6 nowrap | Nov 11, 1860 –Jul 16, 1868 | rowspan=6 colspan=3 | Vacant
|- style="height:2em" | | rowspan=3 | 13
|- style="height:2em"
|- style="height:2em" | rowspan=5 | 14
|- style="height:2em" | | rowspan=5 | 14
|- style="height:2em" ! rowspan=6 | 18 | rowspan=6 align=left | Thomas J. Robertson | rowspan=6 | Republican | rowspan=6 nowrap | Jul 15, 1868 –Mar 3, 1877 | rowspan=3 | Elected to finish the vacant term.
|- style="height:2em" | rowspan=3 | Elected to finish the vacant term. | rowspan=3 nowrap | Jul 16, 1868 –Mar 3, 1873 | rowspan=3 | Republican | rowspan=3 align=right | Frederick A. Sawyer ! rowspan=3 | 13
|- style="height:2em"
|- style="height:2em" | rowspan=3 | Re-elected in 1870.Retired. | rowspan=3 | 15
|- style="height:2em" | | rowspan=3 | 15 | rowspan=3 | Elected in 1872 or 1873. | rowspan=3 nowrap | Mar 4, 1873 –Mar 3, 1879 | rowspan=3 | Republican | rowspan=3 align=right | John J. Patterson ! rowspan=3 | 14
|- style="height:2em"
|- style="height:2em" ! rowspan=9 | 19 | rowspan=9 align=left | Matthew Butler | rowspan=9 | Democratic | rowspan=9 nowrap | Mar 4, 1877 –Mar 3, 1895 | rowspan=3 | Elected in 1876. | rowspan=3 | 16
|- style="height:2em" | | rowspan=3 | 16 | rowspan=3 | Elected in 1878. | rowspan=6 nowrap | Mar 4, 1879 –Mar 3, 1891 | rowspan=6 | Democratic | rowspan=6 align=right | Wade Hampton III ! rowspan=6 | 15
|- style="height:2em"
|- style="height:2em" | rowspan=3 | Re-elected in 1882. | rowspan=3 | 17
|- style="height:2em" | | rowspan=3 | 17 | rowspan=3 | Re-elected in 1884.Lost re-election.
|- style="height:2em"
|- style="height:2em" | rowspan=3 | Re-elected in 1888.Lost renomination. | rowspan=3 | 18
|- style="height:2em" |