| Oaks, | ||
| Ober, Abraham | ||
| Ober, David H. | born 23 Jan 1841, South Woodbury Twp, Bedford County, Pennsylvania, USA | died 01 Mar 1903 |
| Ober, Mary E | born 05 Feb 1853, Woodbury Twp., Bedford County, Pennsylvania, USA | died 30 Mar 1920, Grantham, , Pennsylvania, USA |
| Ober, Mary Sue | born 1849, New Enterprise, Bedford County, Pennsylvania, USA | |
| Oberholtzer, Elizabeth | born 1786 | died 1842 |
| Ochsenbein, Anna Barbara | born 1682 | died 1744 |
| Oellig, Christie | ||
| Oglesby, William | ||
| O'haley, Mary | ||
| Ohlswager, Linda K | ||
| O'Kelly, Hattie | born 14 Dec 1895 | |
| Olsen, George | ||
| Olson, Diana G | ||
| Olson, Leonard | ||
| Olson, Lula | ||
| Oostervelt, Jacob | chr. 21 May 1696, Vlagtwedde, Vlagtwedde, Groningen, Netherlands | |
| Ordway, Jean | ||
| Orndorff, Dustin Allen | ||
| Orndorff, Forrest Glade | ||
| Orndorff, George Foster | born 07 Jan 1924, Sidney, , Nebraska, USA | died 16 Mar 1985, Paradise, Butte County, California, USA |
| Orndorff, Thomas William | ||
| Orr, Pauline J. | ||
| Orthey, Robert | ||
| Osgood, Mehitable | born 07 Jul 1788, Concord, Merrimack County, New Hampshire, USA | died 13 May 1854, Danville, Venango County, Pennsylvania, USA |
| Oshsenbein, Abraham | ||
| Oster, Fred | ||
| Oster, Walter | ||
| Otten, Dena | ||
| Ouderkirk, William R | ||
| Oving, Albertus | born 14 Sep 1919, Buinen, Borger-Odoorn, Drenthe, Netherlands | died 06 Aug 1996, Schoonebeek, Emmen, Drenthe, Netherlands |
| Owen, Jane | ||
| Owens, Joseph |