O
| Representative | Party | District | Years | District home | Note |
|---|---|---|---|---|---|
| James O'Brien | (Independent Democrat) | 1879–1881 | |||
| James H. O'Brien | Democratic | 9th | March 4, 1913 – March 4, 1915 | ||
| Joseph J. O'Brien | Republican | 1939–1945 | |||
| Leo W. O'Brien | Democratic | 1952–1966 | |||
| David J. O'Connell | Democratic | 9th | March 4, 1919 – March 4, 1921 | ||
| March 4, 1923 – December 29, 1930 | Died | ||||
| John J. O'Connor | Democratic | 16th | November 6, 1923 – January 3, 1939 | ||
| Caroline O'Day (At Large) | Democratic | 1935–1943 | |||
| James M.E. O'Grady | Republican | 1899–1901 | |||
| Denis O'Leary | Democratic | 2nd | March 4, 1913 – December 31, 1914 | Resigned | |
| James A. O'Leary | Democratic | 11th | January 3, 1935 – March 16, 1944 | Died | |
| Daniel O'Reilly | Democratic | 2nd | March 4, 1879 – March 4, 1881 | ||
| Donald L. O'Toole | Democratic | 8th | January 3, 1937 – January 3, 1945 | ||
| 13th | January 3, 1945 – January 3, 1953 | ||||
| Thomas J. Oakley | Federalist | 4th | March 4, 1813 – March 4, 1815 | ||
| Jacksonian | 5th | March 4, 1827 – May 9, 1828 | Resigned after being appointed judge of the Superior Court of New York City | ||
| Benjamin B. Odell, Jr. | Republican | 17th | March 4, 1895 – March 4, 1899 | ||
| Moses F. Odell | Democratic | 2nd | March 4, 1861 – March 4, 1863 | ||
| 3rd | March 4, 1863 – March 4, 1865 | ||||
| Nathaniel H. Odell | Democratic | 12th | March 4, 1875 – March 4, 1877 | ||
| David A. Ogden | Federalist | 18th | March 4, 1817 – March 4, 1819 | ||
| Woodson R. Oglesby | Democratic | 1913–1917 | |||
| J. Van Vechten Olcott | Republican | 15th | March 4, 1905 – March 4, 1911 | ||
| Abram B. Olin | Republican | 13th | March 4, 1857 – March 4, 1863 | ||
| Andrew Oliver | Democratic | 1853–1857 | |||
| Daniel C. Oliver | Democratic | 1917–1919 | |||
| Frank A. Oliver | Democratic | 1923–1934 | |||
| Harold C. Ostertag | Republican | 1951–1965 | |||
| Norton P. Otis | Republican | 19th | March 4, 1903 – February 20, 1905 | Died | |
| Richard Ottinger | Democratic | 1965–1971 1975–1985 |
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| Bill Owens | Democratic | 2009–present | |||
| Major R. Owens | Democratic | 12th | January 3, 1983 – January 3, 1993 | ||
| 11th | January 3, 1993 – January 3, 2007 |
Read more about this topic: List Of United States Representatives From New York