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.[1][2][3][4]
Senators who were sworn in during the middle of the Congress (up until the last senator who was not sworn in early after winning the November 1922 election) are listed at the end of the list with no number.
U.S. Senate seniority| Rank | Senator (party-state) | Seniority date | Other factors |
|---|
| 1 | Henry Cabot Lodge (R-MA) | March 4, 1893 |
| 2 | Francis E. Warren (R-WY) | March 4, 1895 | Previously a senator |
| 3 | Knute Nelson (R-MN)[8] | Former governor |
| 4 | Boies Penrose (R-PA)[9] | March 4, 1897 |
| 5 | Charles A. Culberson (D-TX)[10] | March 4, 1899 | Former governor |
| 6 | Porter McCumber (R-ND)[10] | |
| 7 | William P. Dillingham (R-VT) | October 18, 1900 |
| 8 | Furnifold M. Simmons (D-NC) | March 4, 1901 |
| 9 | Lee S. Overman (D-NC) | March 4, 1903 | North Carolina 15th in population (1900) |
| 10 | Reed Smoot (R-UT) | Utah 41st in population (1900) |
| 11 | Frank B. Brandegee (R-CT) | May 10, 1905 | |
| 12 | Robert M. La Follette, Sr. (R-WI) | January 4, 1906 |
| 13 | William Borah (R-ID) | March 4, 1907 |
| 14 | Robert Owen (D-OK) | December 11, 1907 |
| 15 | Carroll S. Page (R-VT)[10] | October 21, 1908 |
| 16 | Albert B. Cummins (R-IA) | November 24, 1908 |
| 17 | Wesley Jones (R-WA) | March 4, 1909 | Former representative |
| 18 | Ellison D. Smith (D-SC) | South Carolina 24th in population (1900) |
| 19 | Duncan U. Fletcher (D-FL) | Florida 33rd in population (1900) |
| 20 | Claude A. Swanson (D-VA) | August 1, 1910 |
| 21 | John S. Williams (D-MS)[10] | March 4, 1911 | Former representative (16 years) |
| 22 | Charles Townsend (D-MI)[10] | Former representative (8 years) |
| 23 | Gilbert Hitchcock (D-NE)[10] | Former representative (6 years) |
| 24 | Miles Poindexter (D-MI)[10] | Former representative (2 years) |
| 25 | George P. McLean (R-CT) | Former governor |
| 26 | Atlee Pomerene (D-OH)[10] | Ohio 4th in population (1910) |
| 27 | James A. Reed (D-MO) | Missouri 7th in population (1910) |
| 28 | Henry L. Myers (D-MT)[10] | Montana 40th in population (1910) |
| 29 | William S. Kenyon (R-IA) | April 12, 1911 |
| 30 | Henry F. Ashurst (D-AZ) | March 27, 1912 | Arizona 45th in population (1910) |
| 31 | Key Pittman (D-NV) | January 29, 1913 | |
| 32 | Morris Sheppard (D-TX) | February 3, 1913 |
| 33 | Joseph E. Ransdell (D-LA) | March 4, 1913 | Former representative (14 years) |
| 34 | Joseph Robinson (R-AR) | Former representative (10 years), former governor |
| 35 | George W. Norris (R-NE) | Former representative (10 years) |
| 36 | John Shields (D-TN) | Tennessee 17th in population (1910) |
| 37 | Thomas Sterling (R-SD) | South Dakota 36th in population (1910) |
| 38 | LeBaron Colt (R-RI) | Rhode Island 38th in population (1910) |
| 39 | Thomas J. Walsh (D-MT) | Montana 40th in population (1910) |
| 40 | Charles Curtis (R-KS) | March 4, 1915 | Previously a senator |
| 41 | Oscar Underwood (D-AL) | Former representative |
| 42 | James Wadsworth, Jr. (R-NY) | |
| 43 | Bert Fernald (R-ME) | September 12, 1916 |
| 44 | James Watson (R-IN) | November 8, 1916 |
| 45 | Philander C. Knox (R-PA)[11] | March 4, 1917 | Previously a senator |
| 46 | William M. Calder (R-NY)[10] | Former representative (10 years) |
| 47 | Kenneth McKellar (D-TN) | Former representative (6 years) |
| 48 | Howard Sutherland (R-WV) | Former representative (4 years) |
| 49 | William H. King (D-UT) | Former representative (3 years) |
| 50 | Peter Gerry (D-RI) | Former representative (2 years) |
| 51 | Park Trammell (D-FL) | Former governor, Florida 33rd in population (1910) |
| 52 | John B. Kendrick (D-WY) | Former governor, Wyoming 47th in population (1910) |
| 53 | Harry S. New (R-IN)[10] | Indiana 9th in population (1910) |
| 54 | Joseph S. Frelinghuysen (R-NJ)[10] | New Jersey 11th in population (1910) |
| 55 | Frank B. Kellogg (R-MN)[10] | Minnesota 19th in population (1910) |
| 56 | Joseph I. France (R-MD)[10] | Maryland 27th in population (1910) |
| 57 | Frederick Hale (R-ME) | Maine 34th in population (1910) |
| 58 | Andrieus Jones (R-NM) | New Mexico 43rd in population (1910) |
| 59 | Josiah Wolcott (D-DE)[12] | Delaware 46th in population (1910) |
| 60 | Hiram Johnson (R-CA) | March 16, 1917 | |
| 61 | Irvine Lenroot (R-WI) | April 18, 1918 |
| 62 | Selden P. Spencer (R-MO) | November 6, 1918 | Missouri 7th in population (1910) |
| 63 | George H. Moses (R-NH) | New Hampshire 39th in population (1910) |
| 64 | Charles L. McNary (R-OR) | December 18, 1918 |
| 65 | Heisler Ball (R-DE) | March 4, 1919 | Previously a senator (2 years) |
| 66 | Davis Elkins (R-WV) | Previously a senator (1 year) |
| 67 | Medill McCormick (R-IL) | Former representative (2 years) |
| 68 | Truman Newberry (R-MI)[13] | Former cabinet member |
| 69 | David I. Walsh (D-MA) | Former governor, Massachusetts 6th in population (1910) |
| 70 | Arthur Capper (R-KS) | Former governor, Kansas 22nd in population (1910) |
| 71 | Henry W. Keyes (R-NH) | Former governor, New Hampshire 39th in population (1910) |
| 72 | William J. Harris (D-GA) | Georgia 10th in population (1910) |
| 73 | Nathaniel Dial (D-SC) | South Carolina 26th in population (1910) |
| 74 | Lawrence C. Phipps (R-CO) | Colorado 32nd in population (1910) |
| 75 | Pat Harrison (D-MS) | March 5, 1919 | Former representative (8 years) |
| 76 | Augustus O. Stanley (D-KY) | May 19, 1919 | Former representative (12 years) |
| 77 | Walter E. Edge (R-NJ) | Former governor, New Jersey 11th in population (1910) |
| 78 | Carter Glass (D-VA) | February 2, 1920 | |
| 79 | James Thomas Heflin (D-AL) | November 2, 1920 |
| 80 | Frank B. Willis (R-OH) | January 14, 1921 |
| 81 | Frank R. Gooding (R-ID) | January 15, 1921 |
| 82 | William B. McKinley (R-IL) | March 4, 1921 | Former representative (14 years) |
| 83 | Thaddeus H. Caraway (D-AR) | Former representative (8 years) |
| 84 | Tom Watson (D-GA)[14] | Former representative (2 years), Georgia 12th in population (1920) |
| 85 | John Harreld (R-OK) | Former representative (2 years), Oklahoma 21st in population (1920) |
| 86 | Ralph H. Cameron (R-AZ) | Former delegate |
| 87 | Peter Norbeck (R-SD) | Former governor, South Dakota 37th in population (1920) |
| 88 | Samuel M. Shortridge (R-CA) | California 8th in population (1920) |
| 89 | Richard P. Ernst (R-KY) | Kentucky 15th in population (1920) |
| 90 | Edwin S. Broussard (D-LA) | Louisiana 22nd in population (1920) |
| 91 | Ovington Weller (R-MD) | Maryland 28th in population (1920) |
| 92 | Samuel Nicholson (D-CO) | Colorado 33rd in population (1920) |
| 93 | Robert Stanfield (R-OR) | Oregon 34th in population (1920) |
| 94 | Edwin Ladd (R-ND) | North Dakota 36th in population (1920) |
| 95 | Tasker Oddie (R-NV) | Nevada 48th in population (1920) |
| Holm O. Bursum (R-NM) | March 11, 1921 | |
| Coleman du Pont (D-DE)[15] | July 7, 1921 |
| William E. Crow (R-PA)[16] | October 24, 1921 |
| George W. Pepper (R-PA) | January 10, 1922 |
| Charles Rawson (R-IA)[17] | February 24, 1922 |
| David A. Reed (R-PA) | August 8, 1922 |
| Thomas F. Bayard, Jr. (D-DE) | November 7, 1922 |
| Rebecca Felton (D-GA)[18] | November 21, 1922 |
| Walter F. George (D-GA) | November 22, 1922 | |
| James Couzens (R-MI) | November 29, 1922 |
| Smith W. Brookhart (R-IA) | December 1, 1922 | Iowa 16th in population (1920) |
|
1. ^[https://www.senate.gov/artandhistory/history/common/briefing/senators_chronological.htm A Chronological List of United States Senators 1789-Present], via www.Senate.gov
2. ^1901 U.S Census Report Contains 1900 Census results
3. ^1911 U.S Census Report Contains 1910 Census results
4. ^1921 U.S Census Report Contains 1920 Census results
5. ^Terms of service of senators that will expire in 1923.
6. ^Terms of service of senators that will expire in 1925.
7. ^Terms of service of senators that will expire in 1927.
8. ^Senator Nelson died April 28, 1923.
9. ^Senator Penrose died December 31, 1921.
10. ^1 2 3 4 5 6 7 8 9 10 11 12 13 Retired or defeated after 1922 Election
11. ^Senator Knox died October 12, 1921.
12. ^Senator Wolcott resigned July 2, 1921.
13. ^Senator Newberry resigned November 18, 1922.
14. ^Senator Watson died September 26, 1922.
15. ^Senator du Pont resigned November 6, 1922.
16. ^Senator Crow died August 2, 1922.
17. ^Senator Rawson resigned December 1, 1922.
18. ^Senator Felton resigned November 21, 1922.