List of former members of the United States House of Representatives (O) Number of years/terms representative/delegate has served Number of years/terms representative/delegate has served

| Representative | Years | State_ | Party | Lifespan |
|---|---|---|---|---|
| Harrison Gray Otis | 1797–1801 | Massachusetts | Federalist | 1765–1848 |
| John Otis | 1849–1851 | Maine | Whig | 1801–1856 |
| John G. Otis | 1891–1893 | Kansas | Populist | 1838–1916 |
| Norton P. Otis | 1903–1905 | New York | Republican | 1840–1905 |
| Theobald Otjen | 1895–1907 | Wisconsin | Republican | 1851–1924 |
| Butch Otter | 2001–2007 | Idaho | Republican | 1942– |
| Richard Ottinger | 1965–1971 1975–1985 | New York | Democratic | 1929– |
| Joseph H. Outhwaite | 1885–1895 | Ohio | Democratic | 1841–1907 |
| George E. Outland | 1943–1947 | California | Democratic | 1906–1981 |
| David Outlaw | 1847–1853 | North Carolina | Whig | 1806–1868 |
| George Outlaw | 1825 | North Carolina | Democratic-Republican | 1731–1825 |
| Arthur W. Overmyer | 1915–1919 | Ohio | Democratic | 1879–1952 |
| James Overstreet | 1819–1822 | South Carolina | Democratic-Republican | 1773–1822 |
| James W. Overstreet | 1906–1907 1917–1923 | Georgia | Democratic | 1866–1938 |
| Jesse Overstreet | 1895–1909 | Indiana | Republican | 1859–1910 |