| CONGRESS | SENATOR | TERM BEGAN | TERM ENDED | COMMENTS |
|---|---|---|---|---|
| Class 1 | ||||
| 51st-52nd | Lyman R. Casey (R) | Nov. 25, 1889 | Mar. 3, 1893 | |
| 53rd-55th | William N. Roach (D) | Mar. 4, 1893 | Mar. 3, 1899 | |
| 56th-67th | Porter J. McCumber (R) | Mar. 4, 1899 | Mar. 3, 1923 | |
| 68th-76th | Lynn J. Frazier (R) | Mar. 4, 1923 | Jan. 3, 1941 | |
| 77th-86th | William Langer (R) | Jan. 3, 1941 | Nov. 8, 1959 | Died |
| 86th | C. Norman Brunsdale (R) | Nov. 19, 1959 | Aug. 7, 1960 | Appointed |
| 86th-102nd | Quentin N. Burdick (D) | Aug. 8, 1960 | Sept. 8, 1992 | Died |
| 102nd | Jocelyn B. Burdick (D) | Sept. 12, 1992 | Dec. 14, 1992 | Appointed |
| 102nd-112th | Kent Conrad (D) | Dec. 14, 1992 | Jan. 3, 2013 | |
| 113th-115th | Mary Kathryn (Heidi) Heitkamp (D) | Jan. 3, 2013 | Jan. 3, 2019 | |
| 116th- | Kevin Cramer (R) | Jan. 3, 2019 | Present | |
| Class 3 | ||||
| 51st | Gilbert A. Pierce (R) | Nov. 21, 1889 | Mar. 3, 1891 | |
| 52nd-60th | Henry C. Hansbrough (R) | Mar. 4, 1891 | Mar. 3, 1909 | |
| 61st | Martin N. Johnson (R) | Mar. 4, 1909 | Oct. 21, 1909 | Died |
| 61st | Fountain L. Thompson (D) | Nov. 10, 1909 | Jan. 31, 1910 | Appointed; resigned |
| 61st | William E. Purcell (D) | Feb. 1, 1910 | Feb. 1, 1911 | Appointed |
| 61st-66th | Asle J. Gronna (R) | Feb. 2, 1911 | Mar. 3, 1921 | |
| 67th-69th | Edwin F. Ladd (R) | Mar. 4, 1921 | Jun. 22, 1925 | Died |
| 69th-78th | Gerald P. Nye (R) | Nov. 14, 1925 | Jan. 3, 1945 | Appointed, then elected |
| 79th | John Moses (D) | Jan. 3, 1945 | Mar. 3, 1945 | Died |
| 79th-96th | Milton R. Young (R) | Mar. 12, 1945 | Jan. 3, 1981 | Appointed, then elected |
| 97th-99th | Mark Andrews (R) | Jan. 3, 1981 | Jan. 3, 1987 | |
| 100th-102nd | Kent Conrad1 (D) | Jan. 3, 1987 | Dec. 14, 1992 | Resigned |
| 102nd-111th | Byron Dorgan (D) | Dec. 14, 19922 | Jan. 3, 2011 | |
| 112th- | John Hoeven (R) | Jan. 3, 2011 | Present | |
1. Resigned Dec. 14, 1992, having been elected in the special election to fill vacancy in the Class 1 seat.
2. Elected to full term commencing Jan. 3, 1993; subsequently appointed by governor to fill vacancy in term ending Jan. 3, 1993.
