R
| Senator | Years | State | Party |
|---|---|---|---|
| George L. P. Radcliffe | 1935–1947 | Maryland | Democratic |
| Samuel M. Ralston | 1923–1925 | Indiana | Democratic |
| Alexander Ramsey | 1863–1875 | Minnesota | Republican |
| Jennings Randolph | 1958–1985 | West Virginia | Democratic |
| John Randolph of Roanoke | 1825–1827 | Virginia | Democratic |
| Theodore Fitz Randolph | 1875–1881 | New Jersey | Democratic |
| Joseph E. Ransdell | 1913–1931 | Louisiana | Democratic |
| Matt W. Ransom | 1872–1895 | North Carolina | Democratic |
| Robert Rantoul, Jr. | 1851 | Massachusetts | Democratic |
| Joseph L. Rawlins | 1897–1903 | Utah | Democratic |
| Charles A. Rawson | 1922 | Iowa | Republican |
| Isidor Rayner | 1905–1912 | Maryland | Democratic |
| George Read | 1789–1793 | Delaware | Federalist |
| Jacob Read | 1795–1801 | South Carolina | Federalist |
| John H. Reagan | 1887–1891 | Texas | Democratic |
| Alfred E. Reames | 1938 | Oregon | Democratic |
| Clyde M. Reed | 1939–1949 | Kansas | Republican |
| David A. Reed | 1922–1935 | Pennsylvania | Republican |
| James A. Reed | 1911–1929 | Missouri | Democratic |
| Philip Reed | 1806–1813 | Maryland | Democratic-Republican |
| Thomas Buck Reed | 1826–1827, 1829 |
Mississippi | Democratic |
| David S. Reid | 1854–1859 | North Carolina | Democratic |
| Hiram Rhodes Revels | 1870–1871 | Mississippi | Republican |
| W. Chapman Revercomb | 1943–1949, 1956–1959 |
West Virginia | Republican |
| Robert Rice Reynolds | 1932–1945 | North Carolina | Democratic |
| Samuel W. Reynolds | 1954 | Nebraska | Republican |
| Robert Rhett | 1850–1852 | South Carolina | Democratic |
| Abraham A. Ribicoff | 1963–1981 | Connecticut | Democratic |
| Benjamin F. Rice | 1868–1872 | Arkansas | Republican |
| 1872–1873 | Liberal Republican | ||
| Henry Mower Rice | 1858–1863 | Minnesota | Democratic |
| Harry A. Richardson | 1907–1913 | Delaware | Republican |
| William Alexander Richardson | 1863–1865 | Illinois | Democratic |
| George R. Riddle | 1864–1867 | Delaware | Democratic |
| Harrison H. Riddleberger | 1883–1889 | Virginia | Readjuster |
| Henry M. Ridgely | 1827–1829 | Delaware | Democratic |
| Donald Riegle | 1977–1995 | Michigan | Democratic |
| William C. Rives | 1832–1834, 1836–1839 |
Virginia | Democratic |
| 1841–1845 | Whig | ||
| William N. Roach | 1893–1899 | North Dakota | Democratic |
| William H. Roane | 1837–1841 | Virginia | Democratic |
| Chuck Robb | 1989–2001 | Virginia | Democratic |
| Asher Robbins | 1825–1836 | Rhode Island | National Republican |
| 1836–1839 | Whig | ||
| Jonathan Roberts | 1814–1821 | Pennsylvania | Democratic-Republican |
| A. Willis Robertson | 1946–1967 | Virginia | Democratic |
| Edward V. Robertson | 1943–1949 | Wyoming | Republican |
| Thomas J. Robertson | 1868–1877 | South Carolina | Republican |
| Arthur R. Robinson | 1925–1935 | Indiana | Republican |
| John M. Robinson | 1830–1841 | Illinois | Democratic |
| Jonathan Robinson | 1807–1815 | Vermont | Democratic-Republican |
| Joseph Taylor Robinson | 1913–1937 | Arkansas | Democratic |
| Moses Robinson | 1791–1797 | Vermont | Democratic-Republican |
| John M. Robsion | 1930 | Kentucky | Republican |
| Julius Rockwell | 1854–1855 | Massachusetts | Whig |
| Caesar A. Rodney | 1822–1823 | Delaware | Democratic-Republican |
| Daniel Rodney | 1826–1827 | Delaware | National Republican |
| Edward H. Rollins | 1877–1883 | New Hampshire | Republican |
| Elihu Root | 1909–1915 | New York | Republican |
| Joseph Rosier | 1941–1942 | West Virginia | Democratic |
| Edmund G. Ross | 1866–1871 | Kansas | Republican |
| James Ross | 1794–1803 | Pennsylvania | Federalist |
| Jonathan Ross | 1899–1900 | Vermont | Republican |
| William V. Roth, Jr. | 1971–2001 | Delaware | Republican |
| John Rowan | 1825–1831 | Kentucky | Democratic |
| Warren Rudman | 1981–1993 | New Hampshire | Republican |
| Benjamin Ruggles | 1815–1824 | Ohio | Democratic-Republican |
| 1824–1833 | National Republican | ||
| John Ruggles | 1835–1841 | Maine | Democratic |
| Thomas Jefferson Rusk | 1846–1857 | Texas | Democratic |
| Donald S. Russell | 1965–1966 | South Carolina | Democratic |
| Richard Russell, Jr. | 1933–1971 | Georgia | Democratic |
| John Rutherfurd | 1791–1798 | New Jersey | Federalist |
Read more about this topic: List Of Former United States Senators