K
| Senator | Years | State | Party |
|---|---|---|---|
| Elias Kane | 1825–1835 | Illinois | Democratic |
| David Karnes | 1987–1989 | Nebraska | Republican |
| Nancy Landon Kassebaum | 1979–1997 | Kansas | Republican |
| Robert W. Kasten Jr. | 1981–1993 | Wisconsin | Republican |
| Ted Kaufman | 2009–2010 | Delaware | Democratic |
| William M. Kavanaugh | 1913 | Arkansas | Democratic |
| Hamilton Fish Kean | 1929–1935 | New Jersey | Republican |
| John Kean | 1899–1911 | New Jersey | Republican |
| Thomas Kearns | 1901–1905 | Utah | Republican |
| Kenneth Keating | 1959–1965 | New York | Republican |
| Estes Kefauver | 1949–1963 | Tennessee | Democratic |
| Frank B. Kellogg | 1917–1923 | Minnesota | Republican |
| William P. Kellogg | 1868–1872, 1877–1883 |
Louisiana | Republican |
| James K. Kelly | 1871–1877 | Oregon | Democratic |
| William Kelly | 1822–1825 | Alabama | Democratic-Republican |
| James P. Kem | 1947–1953 | Missouri | Republican |
| Dirk Kempthorne | 1993–1999 | Idaho | Republican |
| John B. Kendrick | 1917–1933 | Wyoming | Democratic |
| John E. Kenna | 1883–1893 | West Virginia | Democratic |
| Anthony Kennedy | 1857–1863 | Maryland | American |
| Ted Kennedy | 1962–2009 | Massachusetts | Democratic |
| John F. Kennedy | 1953–1961 | Massachusetts | Democratic |
| Robert F. Kennedy | 1965–1968 | New York | Democratic |
| Richard R. Kenney | 1897–1901 | Delaware | Democratic |
| Joseph Kent | 1833–1837 | Maryland | Whig |
| William S. Kenyon | 1911–1922 | Iowa | Republican |
| John W. Kern | 1911–1917 | Indiana | Democratic |
| Francis Kernan | 1875–1881 | New York | Democratic |
| John Leeds Kerr | 1841–1843 | Maryland | Whig |
| Joseph Kerr | 1814–1815 | Ohio | Democratic-Republican |
| Robert S. Kerr | 1949–1963 | Oklahoma | Democratic |
| Bob Kerrey | 1989–2001 | Nebraska | Democratic |
| David M. Key | 1875–1877 | Tennessee | Democratic |
| Henry W. Keyes | 1919–1937 | New Hampshire | Republican |
| Harley M. Kilgore | 1941–1956 | West Virginia | Democratic |
| John Pendleton King | 1833–1837 | Georgia | Democratic |
| Preston King | 1857–1863 | New York | Republican |
| Rufus King | 1789–1796, 1813–1825 |
New York | Federalist |
| William H. King | 1917–1941 | Utah | Democratic |
| William R. King | 1819–1844, 1848–1852 |
Alabama | Democratic |
| William F. Kirby | 1916–1921 | Arkansas | Democratic |
| Paul G. Kirk | 2009–2010 | Massachusetts | Democratic |
| Samuel J. Kirkwood | 1866–1867, 1877–1881 |
Iowa | Republican |
| Aaron Kitchell | 1805–1809 | New Jersey | Democratic-Republican |
| Alfred B. Kittredge | 1901–1909 | South Dakota | Republican |
| Nehemiah R. Knight | 1821–1824 | Rhode Island | Democratic-Republican |
| 1824–1832 | National Republican | ||
| 1832–1841 | Whig | ||
| William F. Knowland | 1945–1959 | California | Republican |
| Philander Chase Knox | 1904–1909, 1917–1921 |
Pennsylvania | Republican |
| Bob Krueger | 1993 | Texas | Democratic |
| Tom Kuchel | 1953–1969 | California | Republican |
| James H. Kyle | 1891–1901 | South Dakota | Populist |
Read more about this topic: List Of Former United States Senators