| Steven O'DONNELL (1870-1940) | & | Caroline Mary NEUHOFER (1875-1959) |
| Alfred Joseph OGLE (1826-1874) | & | Roxanna Elizabeth STARNES (1833-1900) |
| Patrick O'LEARY (????-1875) | & | Julia MOYNIHAN (????-1875) |
| Charles O'MORROW (????-????) | & | ? (????-????) |
| Peter OPDYKE (1777-1844) | & | Hannah LUCE (1778-1850) |
| Alexander ORAHOOD (????-1800) | & | Eve STOOKEY (????-1804) |
| Amos ORAHOOD (1893-1870) | & | Susanna BONNER (1799-1860) |
| Caleb ORAHOOD (1763-1840) | & | Phebe CUBBERLY (1776-1839) |
| Caleb ORAHOOD (1805-1845) | & | Elizabeth "Betsy" SHIRK (1808-1898) |
| Daniel ORAHOOD (1792-1838) | & | Sarah "Sally" ANDREWS (1803-1875) |
| Elijah ORAHOOD (1798-1860) | & | Rachel "Sarah" CARTER (????-1835) |
| Elijah ORAHOOD (1798-1860) | & | unknown (????-????) |
| Jacob ORAHOOD (1804-1873) | & | Priscilla GARRET (1806-1860) |
| James ORAHOOD (1792-1857) | & | Elizabeth BOYD (????-1824) |
| James ORAHOOD (1792-1857) | & | Mary "Polly" LILLY (1801-1848) |
| James ORAHOOD (1792-1857) | & | Ursula PRATER (1808-1887) |
| Samuel ORAHOOD (1791-1871) | & | Mary "Polly" DIXON (1793-1851) |
| Thomas ORAHOOD (1798-1860) | & | Catherine "Catie" BOWERS (????-1831) |
| Thomas ORCHARD (1760-1845) | & | Sarah "Sally" NORMAN (1764-1854) |
| Ephraim L. ORR (1831-1910) | & | Melissa A. WEEKS (1843-1875) |
| Benjamin OSBORNE (1853-1930) | & | Carrie M. SWEENY (1853-1929) |
| Samuel OVERHULSE (1820-1898) | & | Susannah Bell GRAHAM (1822-1856) |
| Samuel OVERHULSE (1820-1898) | & | Eliza Ann VIRICK (1839-????) |
| Joseph OWEN (1759-1827) | & | Susanna NEWELL (1769-1848) |
