Louisiana was admitted to the Union on April 30, 1812, and elects senators to class 2 and class 3. Russell Long was the state's longest-serving senator, serving from 1948–1987. Its current senators are Republicans Bill Cassidy and John Kennedy.
Louisiana is one of eighteen states alongside California, Colorado, Delaware, Georgia, Hawaii, Idaho, Maine, Massachusetts, Minnesota, Missouri, Nevada, Oklahoma, Pennsylvania, South Carolina, South Dakota, Utah, and West Virginia to have a younger senior senator and an older junior senator.
List of senators
|- style="height:2em" | colspan=3 | Vacant | Apr 30, 1812 –Sep 3, 1812 | Louisiana did not elect its senators until four months after statehood. | rowspan=7 | 1 | rowspan=5 | rowspan=5 | 1 | Louisiana did not elect its senators until four months after statehood. | Apr 30, 1812 –Sep 3, 1812 | colspan=3 | Vacant
|- style="height:2em" ! 1 | align=left | Jean Noël Destréhan | | Democratic-Republican | nowrap | Sep 3, 1812 –Oct 1, 1812 | Resigned | rowspan=4 | Elected in 1812. | rowspan=4 nowrap | Sep 3, 1812 –Mar 3, 1813 | rowspan=4 | Democratic-Republican | rowspan=4 align=right | Allan B. Magruder ! rowspan=4 | 1
|- style="height:2em" | colspan=3 | Vacant | nowrap | Oct 1, 1812 –Oct 8, 1812
|- style="height:2em" ! 2 | align=left | Thomas Posey | | Democratic-Republican | nowrap | Oct 8, 1812 –Feb 4, 1813 | Appointed to continue Destréhan's term.Lost election to finish Destréhan's term.
|- style="height:2em" ! rowspan=3 | 3 | rowspan=3 align=left | James Brown | rowspan=3 | Democratic-Republican | rowspan=3 nowrap | Feb 5, 1813 –Mar 3, 1817 | rowspan=3 | Elected to finish Destréhan's term.Lost election to full term.
|- style="height:2em" | | rowspan=5 | 2 | rowspan=5 | Elected in 1813Retired. | rowspan=5 nowrap | Mar 4, 1813 –Mar 3, 1819 | rowspan=5 | Democratic-Republican | rowspan=5 align=right | Eligius Fromentin ! rowspan=5 | 2
|- style="height:2em"
|- style="height:2em" ! 4 | align=left | William C. C. Claiborne | | Democratic-Republican | nowrap | Mar 4, 1817 –Nov 23, 1817 | Elected in 1817.Died. | rowspan=5 | 2 | rowspan=3
|- style="height:2em" | colspan=3 | Vacant | nowrap | Nov 23, 1817 –Jan 12, 1818
|- style="height:2em" ! rowspan=6 | 5 | rowspan=6 align=left | Henry Johnson | rowspan=6 | Democratic-Republican | rowspan=6 nowrap | Jan 12, 1818 –May 27, 1824 | rowspan=3 | Elected to finish Claiborne's term.
|- style="height:2em" | | rowspan=7 | 3 | rowspan=3 | Elected in 1819.Resigned to become U.S. Minister to France. | rowspan=3 nowrap | Mar 4, 1819 –Dec 10, 1823 | rowspan=3 | Democratic-Republican | rowspan=3 align=right | James Brown ! rowspan=3 | 3
|- style="height:2em"
|- style="height:2em" | rowspan=3 | Elected to full term in 1823.Resigned to become Governor of Louisiana. | rowspan=7 | 3 | rowspan=5
|- style="height:2em"
| nowrap | Dec 10, 1823 –Jan 15, 1824 | colspan=3 | Vacant
|- style="height:2em" | rowspan=3 | Elected to finish Brown's term. | rowspan=10 nowrap | Jan 15, 1824 –May 19, 1833 | rowspan=3 | Democratic-Republican | rowspan=10 align=right | Josiah S. Johnston ! rowspan=10 | 4
|- style="height:2em" | colspan=3 | Vacant | nowrap | May 27, 1824 –Nov 19, 1824
|- style="height:2em" ! rowspan=3 | 6 | rowspan=3 align=left | Dominique Bouligny | | Democratic-Republican | rowspan=3 nowrap | Nov 19, 1824 –Mar 3, 1829 | rowspan=3 | Elected to finish Johnson's term.
|- style="height:2em" | rowspan=2 | NationalRepublican | | rowspan=3 | 4 | rowspan=3 | Elected to full term in 1825. | rowspan=7 | NationalRepublican
|- style="height:2em"
|- style="height:2em" ! rowspan=2 | 7 | rowspan=2 align=left | Edward Livingston | rowspan=2 | Jacksonian | rowspan=2 nowrap | Mar 4, 1829 –May 24, 1831 | rowspan=2 | Elected in 1829.Resigned to become U.S. Secretary of State. | rowspan=7 | 4
|- style="height:2em" | rowspan=3 | rowspan=10 | 5 | rowspan=4 | Re-elected in 1831.Died.
|- style="height:2em" | colspan=3 | Vacant | nowrap | May 24, 1831 –Nov 15, 1831
|- style="height:2em" ! rowspan=4 | 8 | rowspan=4 align=left | George A. Waggaman | rowspan=4 | NationalRepublican | rowspan=4 nowrap | Nov 15, 1831 –Mar 3, 1835 | rowspan=4 | Elected to finish Livingston's term.
|- style="height:2em" | rowspan=3
|- style="height:2em"
| nowrap | May 19, 1833 –Dec 19, 1833 | colspan=3 | Vacant
|- style="height:2em" | rowspan=3 | Elected to finish Johnston's term.Resigned due to ill health. | rowspan=3 nowrap | Dec 19, 1833 –Jan 5, 1837 | rowspan=3 | NationalRepublican | rowspan=3 align=right | Alexander Porter ! rowspan=3 | 5
|- style="height:2em" | colspan=3 | Vacant | nowrap | Mar 4, 1835 –Jan 13, 1836 | Charles Gayarré (J) was elected in 1835, but resigned due to ill health. | rowspan=6 | 5 | rowspan=4
|- style="height:2em" ! rowspan=5 | 9 | rowspan=5 align=left | Robert C. Nicholas | rowspan=3 | Jacksonian | rowspan=5 nowrap | Jan 13, 1836 –Mar 3, 1841 | rowspan=5 | Elected to finish Gauarré's term.
|- style="height:2em"
| nowrap | Jan 5, 1837 –Jan 12, 1837 | colspan=3 | Vacant
|- style="height:2em" | Elected to finish Porter's term. | rowspan=4 nowrap | Jan 12, 1837 –Mar 1, 1842 | | Jacksonian | rowspan=4 align=right | Alexandre Mouton ! rowspan=4 | 6
|- style="height:2em" | rowspan=2 | Democratic | | rowspan=5 | 6 | rowspan=3 | Re-elected in 1837.Resigned. | rowspan=3 | Democratic
|- style="height:2em"
|- style="height:2em" ! rowspan=7 | 10 | rowspan=7 align=left | Alexander Barrow | rowspan=7 | Whig | rowspan=7 nowrap | Mar 4, 1841 –Dec 29, 1846 | rowspan=7 | Elected in 1840.Died. | rowspan=9 | 6 | rowspan=3
|- style="height:2em"
| nowrap | Mar 1, 1842 –Apr 14, 1842 | colspan=3 | Vacant
|- style="height:2em" | Appointed to finish Mouton's term.Lost election to full term. | nowrap | Apr 14, 1842 –Mar 3, 1843 | | Whig | align=right | Charles Conrad ! 7
|- style="height:2em" | rowspan=3 | rowspan=7 | 7 | Elected in 1843, but due to ill health did not take his seat.Died. | nowrap | Mar 4, 1843 –Jan 13, 1844 | | Whig | align=right | Alexander Porter ! 8
| nowrap | Jan 13, 1844 –Feb 12, 1844 | colspan=3 | Vacant
|- style="height:2em" | rowspan=5 |Elected to finish Porter's termLost election to full term in 1849. | rowspan=5 nowrap | Feb 12, 1844 –Mar 3, 1849 | rowspan=5 | Whig | rowspan=5 align=right | Henry Johnson ! rowspan=5 | 9
|- style="height:2em" | rowspan=3
|- style="height:2em" | colspan=3 | Vacant | nowrap | Dec 29, 1846 –Jan 21, 1847
|- style="height:2em" ! 11 | align=left | Pierre Soulé | | Democratic | nowrap | Jan 21, 1847 –Mar 3, 1847 | Elected to finish Barrow's term.
|- style="height:2em" ! rowspan=3 | 12 | rowspan=3 align=left | Solomon W. Downs | rowspan=3 | Democratic | rowspan=3 nowrap | Mar 4, 1847 –Mar 3, 1853 | rowspan=3 | Elected in 1847.Lost re-election. | rowspan=3 | 7
|- style="height:2em" | | rowspan=5 | 8 | rowspan=3 | Elected in 1848.Resigned to become U.S. Minister to Spain. | rowspan=3 nowrap | Mar 3, 1849 –Apr 11, 1853 | rowspan=3 | Democratic | rowspan=3 align=right | Pierre Soulé ! rowspan=3 | 10
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|- style="height:2em" ! rowspan=6 | 13 | rowspan=6 align=left | Judah P. Benjamin | rowspan=4 | Whig | rowspan=6 nowrap | Mar 4, 1853 –Feb 4, 1861 | rowspan=5 | Elected in 1852. | rowspan=5 | 8 | rowspan=3
|- style="height:2em"
| nowrap | Apr 11, 1853 –Dec 5, 1853 | colspan=3 | Vacant
|- style="height:2em" | Elected to finish Soulé's term. | rowspan=4 nowrap | Dec 5, 1853 –Feb 4, 1861 | rowspan=4 | Democratic | rowspan=4 align=right | John Slidell ! rowspan=4 | 11
|- style="height:2em" | | rowspan=4 | 9 | rowspan=3 | Re-election year unknown.Resigned.
|- style="height:2em" | rowspan=2 | Democratic
|- style="height:2em" | Re-elected in 1859.Withdrew. | rowspan=4 | 9 | rowspan=2
|- style="height:2em" | rowspan=5 colspan=3 | Vacant | rowspan=5 nowrap | Feb 4, 1861 –Jul 8, 1868 | rowspan=5 | Civil War and Reconstruction | rowspan=6 | Civil War and Reconstruction | rowspan=6 nowrap | Feb 4, 1861 –Jul 9, 1868 | rowspan=6 colspan=3 | Vacant
|- style="height:2em" | | rowspan=3 | 10
|- style="height:2em"
|- style="height:2em" | rowspan=5 | 10
|- style="height:2em" | rowspan=3 | rowspan=6 | 11
|- style="height:2em" ! rowspan=3 | 14 | rowspan=3 align=left | John S. Harris | rowspan=3 | Republican | rowspan=3 nowrap | Jul 8, 1868 –Mar 3, 1871 | rowspan=3 | Elected to finish incomplete term in 1868..
|- style="height:2em" | rowspan=3 | Elected to finish incomplete term.Resigned to become Governor of Louisiana. | rowspan=3 nowrap | Jul 9, 1868 –Nov 1, 1872 | rowspan=3 | Republican | rowspan=3 align=right | William Pitt Kellogg ! rowspan=3 | 12
|- style="height:2em"
|- style="height:2em" ! rowspan=5 | 15 | rowspan=5 align=left | J. R. West | rowspan=5 | Republican | rowspan=5 nowrap | Mar 4, 1871 –Mar 3, 1877 | rowspan=5 | Election year unknown.Retired. | rowspan=5 | 11 | rowspan=2
|- style="height:2em" | rowspan=3 | Senate declined to seat rival claimants William L. McMillen and P. B. S. Pinchback | rowspan=3 nowrap | Nov 1, 1872 –Jan 12, 1876 | rowspan=3 colspan=3 | Vacant
|- style="height:2em" | | rowspan=4 | 12
|- style="height:2em" | rowspan=2
|- style="height:2em" | rowspan=2 | Elected to finish incomplete term in 1876.Lost re-election. | rowspan=2 nowrap | Jan 12, 1876 –Mar 3, 1879 | rowspan=2 | Democratic | rowspan=2 align=right | James B. Eustis ! rowspan=2 | 13
|- style="height:2em" ! rowspan=3 | 16 | rowspan=3 align=left | William Pitt Kellogg | rowspan=3 | Republican | rowspan=3 nowrap | Mar 4, 1877 –Mar 3, 1883 | rowspan=3 | Elected in 1876.Retired to run for U.S. House. | rowspan=3 | 12
|- style="height:2em" | | rowspan=3 | 13 | rowspan=3 | Elected in 1879.Lost re-election. | rowspan=3 nowrap | Mar 4, 1879 –Mar 3, 1885 | rowspan=3 | Democratic | rowspan=3 align=right | Benjamin F. Jonas ! rowspan=3 | 14
|- style="height:2em"
|- style="height:2em" ! rowspan=5 | 17 | rowspan=5 align=left | Randall L. Gibson | rowspan=5 | Democratic | rowspan=5 nowrap | Mar 4, 1883 –Dec 15, 1892 | rowspan=3 | Elected in 1882. | rowspan=3 | 13
|- style="height:2em" | | rowspan=3 | 14 | rowspan=3 | Election year unknown.Retired. | rowspan=3 nowrap | Mar 4, 1885 –Mar 3, 1891 | rowspan=3 | Democratic | rowspan=3 align=right | James B. Eustis ! rowspan=3 | 15
|- style="height:2em"
|- style="height:2em" | rowspan=2 | Re-elected in 1889.Died. | rowspan=6 | 14
|- style="height:2em" | rowspan=3 | rowspan=6 | 15 | rowspan=4 | Elected in 1891.Resigned to become U.S. Supreme Court Justice. | rowspan=4 nowrap | Mar 4, 1891 –Mar 12, 1894 | rowspan=4 | Democratic | rowspan=4 align=right | Edward Douglass White ! rowspan=4 | 16
|- style="height:2em" | colspan=3 | Vacant | nowrap | Dec 15, 1892 –Dec 31, 1892
|- style="height:2em" ! rowspan=6 | 18 | rowspan=6 align=left | Donelson Caffery | rowspan=6 | Democratic | rowspan=6 nowrap | Dec 31, 1892 –Mar 3, 1901 | rowspan=3 | Appointed to continue Gibson's term.Elected in 1894 to finish Gibson's term.
|- style="height:2em" | rowspan=2
|- style="height:2em" | rowspan=2 | Appointed to continue White's term.Elected in 1894 to finish White's term.Retired. | rowspan=2 nowrap | Mar 12, 1894 –Mar 3, 1897 | rowspan=2 | Democratic | rowspan=2 align=right | Newton C. Blanchard ! rowspan=2 | 17
|- style="height:2em" | rowspan=3 | Elected in 1894 to the next term, before election to finish Gibson's term.Retired. | rowspan=3 | 15
|- style="height:2em" | | rowspan=3 | 16 | rowspan=3 | Elected in 1896. | rowspan=7 nowrap | Mar 4, 1897 –Jun 28, 1910 | rowspan=7 | Democratic | rowspan=7 align=right | Samuel D. McEnery ! rowspan=7 | 18
|- style="height:2em"
|- style="height:2em" ! rowspan=8 | 19 | rowspan=8 align=left | Murphy J. Foster | rowspan=8 | Democratic | rowspan=8 nowrap | Mar 4, 1901 –Mar 3, 1913 | rowspan=3 | Elected in 1900. | rowspan=3 | 16
|- style="height:2em" | | rowspan=3 | 17 | rowspan=3 | Re-elected early in 1900.
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