List of United States senators in the 18th Congress
# List of United States senators in the 18th Congress

This is a complete list of members of the United States Senate during the 18th United States Congress listed by seniority, from March 4, 1823, to March 3, 1825.

Order of service is based on the commencement of the senator's first term. Behind this is former service as a senator (only giving the senator seniority within his or her new incoming class), service as vice president, a House member, a cabinet secretary, or a governor of a state. The final factor is the population of the senator's state.

Senators who were sworn in during the middle of the two-year congressional term (up until the last senator who was not sworn in early after winning the November 1824 election) are listed at the end of the list with no number.

## Terms of service

| Class | Terms of service of senators that expired in years |
| - | - |
| Class 3 | Terms of service of senators that expired in 1825 |
| Class 1 | Terms of service of senators that expired in 1827 |
| Class 2 | Terms of service of senators that expired in 1829 |

## U.S. Senate seniority list

U.S. Senate seniority :

| Rank | Senator (party-state) | Seniority date | Other factors |
| - | - | - | - |
| 1 | John Gaillard (DR-SC) | December 6, 1804 | |
| 2 | Rufus King (F-NY) | March 4, 1813 |
| 3 | James Barbour (DR-VA) | January 2, 1815 |
| 4 | Benjamin Ruggles (DR-OH) | March 4, 1815 |
| 5 | Nathaniel Macon (DR-NC) | December 5, 1815 |
| 6 | James Noble (DR-IN) | December 11, 1816 | Alphabetical (N) |
| 7 | Waller Taylor (DR-IN) | December 11, 1816 | Alphabetical (T) |
| 8 | Nicholas Van Dyke (DR-DE) | March 4, 1817 | Former representative |
| 9 | Mahlon Dickerson (DR-NJ) | March 4, 1817 |
| 10 | Thomas Hill Williams (DR-MS) | December 10, 1817 |
| 11 | Henry Johnson (DR-LA) | January 12, 1818 |
| 12 | William Adams Palmer (DR-VT) | October 20, 1818 |
| 13 | Jesse Burgess Thomas (DR-IL) | December 3, 1818 | Former delegate |
| 14 | Ninian Edwards (DR-IL) | December 3, 1818 |
| 15 | James Brown (DR-LA) | March 4, 1819 | Former senator |
| 16 | Edward Lloyd (DR-MD) | March 4, 1819 | Former representative (2 years, 3 months) |
| 17 | John Fabyan Parrott (DR-NH) | March 4, 1819 | Former representative (2 years, 0 months) |
| 18 | Walter Lowrie (DR-PA) | March 4, 1819 | Pennsylvania 3rd in population (1810) |
| 19 | James Lanman (DR-CT) | March 4, 1819 | Connecticut 9th in population (1810) |
| 20 | John Elliott (DR-GA) | March 4, 1819 | Georgia 11th in population (1810) |
| 21 | Richard Mentor Johnson (DR-KY) | December 10, 1819 |
| 22 | William Rufus de Vane King (DR-AL) | December 14, 1819 |
| 23 | Elijah Hunt Mills (F-MA) | June 12, 1820 |
| 24 | John Holmes (Maine politician) (DR-ME) | June 13, 1820 |
| 25 | John Chandler (DR-ME) | June 14, 1820 |
| 26 | David Holmes (DR-MS) | August 30, 1820 |
| 27 | Isham Talbot (DR-KY) | October 19, 1820 |
| 28 | Nehemiah Rice Knight (DR-RI) | January 9, 1821 |
| 29 | Martin Van Buren (DR-NY) | March 4, 1821 | New York 1st in population (1810) |
| 30 | Elijah Boardman (DR-CT) | March 4, 1821 | Connecticut 9th in population (1810) |
| 31 | Horatio Seymour (DR-VT) | March 4, 1821 | Vermont 15th in population (1810) |
| 32 | James De Wolf (DR-RI) | March 4, 1821 | Rhode Island 17th in population (1810) |
| 33 | David Barton (DR-MO) | August 10, 1821 | Alphabetical (Ba) |
| 34 | Thomas Hart Benton (DR-MO) | August 10, 1821 | Alphabetical (Be) |
| 35 | John Henry Eaton (DR-TN) | September 27, 1821 |
| 36 | Nicholas Ware (DR-GA) | November 10, 1821 |
| 37 | William Findlay (DR-PA) | December 10, 1821 |
| 38 | Ethan Allen Brown (DR-OH) | January 3, 1822 |
| 39 | James Lloyd (F-MA) | June 5, 1822 |
| 40 | William Kelly (DR-AL) | December 12, 1822 |
| 41 | Samuel Smith (DR-MD) | December 17, 1822 |
| 42 | John Taylor of Caroline (DR-VA) | December 18, 1822 |
| 43 | Andrew Jackson (DR-TN) | March 4, 1823 | Former senator |
| 44 | John Branch (DR-NC) | March 4, 1823 | Former governor; North Carolina 4th in population (1820) |
| 45 | Samuel Bell (DR-NH) | March 4, 1823 | Former governor; New Hampshire 15th in population (1820) |
| 46 | Robert Young Hayne (DR-NH) | March 4, 1823 |
| | Henry Waggaman Edwards (DR-CT) | October 8, 1823 |
| 47 | Joseph McIlvaine (DR-NJ) | November 12, 1823 |
| 48 | Thomas Clayton (F-DE) | January 8, 1824 |
| | Josiah Stoddard Johnston (DR-LA) | January 15, 1824 |
| | Charles Dominique Joseph Bouligny (DR-LA) | November 19, 1824 |
| | John McLean (DR-IL) | November 23, 1824 |
| | Thomas Willis Cobb (DR-GA) | December 6, 1824 |
| | Littleton Waller Tazewell (DR-VA) | December 7, 1824 |
