| Individual's Name | Birth Date | Death Date | | O'Connor, Caroline L. | | |
| O'Donnell, Paul M. | | |
| O'Hara, Joann | | |
| Oakes, Clarence E. | | |
| Oakes, Laurie Ann | 18 APR 1963 | |
| Obama, Auma | | |
| Obama, Barack Hussein | 1936 | 1982 |
| Obama, Barack Hussein | 4 AUG 1961 | |
| Obama, Hussein Onyango | 1895 | 1979 |
| Obama, Malia | 1998 | |
| Obama, Sarah | | |
| Obama, Sasha | 2001 | |
| Oberer, Eva | ABT 1702 | |
| Oberholtzer, Ann | ABT 1678 | |
| Oberholtzer, Miriam L. | | |
| Oberholtzer, Reuben L. | | |
| Oberlandscheidt, Anna Margarete | ABT 1593 | |
| Oberlandscheit, Johann | | |
| Ochenryder, Elsie | ABT 1888 | 1970 |
| Ocher, Mary | | 1860 |
| Oechler, Amanda Rachele | | |
| Oechler, Brian Keith | | |
| Oechler, Lyle | | |
| Oestreich, Heather | | |
| Oestreich, John C. | | |
| Ohl, Abby | | |
| Ohl, Albertina | | |
| Ohl, Albertina | | |
| Ohl, Albertina Philipina | | |
| Ohl, Albertina Phillipina | | |
| Ohl, Andeas | | |
| Ohl, Andreas | 17 AUG 1732 | 26 MAY 1808 |
| Ohl, Anna Catharina | | |
| Ohl, Anna Catharina | | |
| Ohl, Anna Margaretha | | |
| Ohl, Anna Margaretha Elizabetha | | |
| Ohl, Anna Maria | | |
| Ohl, Catherina | | |
| Ohl, Catherine | 25 JAN 1780 | |
| Ohl, Catherine | | |
| Ohl, Catherine | | |
| Ohl, Christina | 05 MAR 1789 | 14 MAY 1874 |
| Ohl, Christina | | |
| Ohl, Edward S. | | |
| Ohl, Elisabetha Barbara | | |
| Ohl, Elizabeth | 1785 | ABT 1879 |
| Ohl, Elizabeth | | |
| Ohl, Elizabeth Barbara | | |
| Ohl, Eva | | |
| Ohl, Eva | | |
| Ohl, Eva | | |
| Ohl, Eva Catherine | | |
| Ohl, Eva Catherine | | |
| Ohl, George | 19 JUN 1784 | 11 MAR 1862 |
| Ohl, Hanna | | |
| Ohl, Hanna | | |
| Ohl, Heinrich | | |
| Ohl, Henry | 1795 | 08 JUN 1853 |
| Ohl, Henry | | |
| Ohl, Henry | | |
| Ohl, Ira Canfield | | |
| Ohl, Jacob | 1 SEP 1808 | 14 JAN 1885 |
| Ohl, Jacob | | |
| Ohl, Johann Conrad | | |
| Ohl, Johann Heinrich | 29 DEC 1664 | |
| Ohl, Johann Nicholas | | |
| Ohl, Johann Nicholas | | |
| Ohl, Johannes | | |
| Ohl, Johannes Heinrich | 10 FEB 1704 | 24 MAR 1785 |
| Ohl, John F. | | |
| Ohl, Lemuel | | |
| Ohl, Lydia | | |
| Ohl, Margaret (Mary) Jane | | |
| Ohl, Maria Barbara | | |
| Ohl, Mary | | |
| Ohl, Mary | | |
| Ohl, Michael | 1750 | 1823 |
| Ohl, Michael | ABT 1784 | |
| Ohl, Michael | 26 JUN 1729 | JUL 1804 |
| Ohl, Michael | | |
| Ohl, Nancy | | |
| Ohl, Nora Ellen | 28 DEC 1877 | 19 JUN 1915 |
| Ohl, Rebecca | | |
| Ohl, Samuel | | |
| Ohl, Sarah Ann | | |
| Ohl, Stephen | | |
| Ohl, Susannah | | |
| Ohl, Wilhelm | | |
| Ohl, William A. | | |
| Ohl, __ | | |
| Ohmit, Donald | | |
| Ohmit, Donald Thomas | 03 SEP 1973 | |
| Oldham, Dorothy | | |
| Oleson, Forest C. | 1896 | |
| Oleson, Mary Christiane | 1891 | |
| Oleson, Ole Christopter | 1862 | |
| Oleson, Rasmus | 1894 | |
| Oleson, Willis Britton | 1894 | |
| Oliva de Alonzo, Ruth Marisol | 9 NOV 1988 | |
| Oliveira, Duane Joseph | | |
| Oliveira, Edward | | |
| Oliveira, Rochelle Franchesca | | |
| Oliver, Lucinda Adaline | 31 AUG 1859 | 16 MAY 1941 |
| Olsen, Avis G. | 1898 | |
| Olsen, Bradley Jerome | 15 SEP 2005 | |
| Olsen, Jace | 19 AUG 1981 | |
| Olsen, Joshua Jerome | 27 OCT 1979 | |
| Olsen, Kalyna Jo | 22 APR 2003 | |
| Olsen, Makyenzi Joy | 10 NOV 2007 | |
| Olsen, Mitchell Jerome | 14 JUL 1953 | |
| Olsen, Richard J. | | |
| Olson, __ | | |
| on Grenzhof, Lusie Schuh | 24 MAY 1921 | |
| Onder, __ | | |
| Orler, Johna Michelle | 1967 | |
| Orndorf, Anna Mary | 28 FEB 1828 | 17 JAN 1880 |
| Orndorf, Beryl Francis | | |
| Orndorf, Beverly Mae | | |
| Orndorf, Charles Maurice | | |
| Orndorf, Elwood | | |
| Orndorf, Eric | ABT 1964 | |
| Orndorf, Lafirne Naomi | | |
| Orndorf, Olive I. | 1913 | 1982 |
| Orndorf, __ | | |
| Orndorff, Elizabeth | | |
| Orndorff, Henry | 1805 | 2 JUL 1873 |
| Orndorff, Hiram | | |
| Orndorff, Jacob H. | | |
| Orndorff, John H. | | |
| Orndorff, Susan A. | | |
| Orr, Harold | | |
| Orr, Tressie G. | | |
| Orth, Harry S. | | |
| Orth, Kathryn M. | | |
| Orth, Williams H. | | |
| Ortiz, Encarnacion | | |
| Ortiz Cameros, Ana Paula | 15 JUN 2006 | |
| Ortiz Noj, Josue Miguel | | |
| Orwig, Catherine | 14 OCT 1813 | |
| Orwig, Mary | 11 MAR 1816 | |
| Osborne, Emma | 10 NOV 1882 | 3 DEC 1961 |
| Osborne, Geary | 1873 | |
| Osborne, John | | |
| Osborne, John Ray | 6 NOV 1904 | 30 AUG 1964 |
| Osborne, Mary Effie | ABT 1874 | |
| Osborne, Osie | 22 DEC 1882 | 2 FEB 1912 |
| Osborne, Ralph Fleshman | 25 JUL 1908 | 12 JUL 1967 |
| Osborne, Samuel | 1 JAN 1851 | 8 FEB 1925 |
| Osborne, Sybil M. | 31 JUL 1898 | ABT 1906 |
| Osborne, Wade Fleshman | 1875 | 1967 |
| Osborne, __ | | |
| Osgood, Helen | | |
| Osman, Blanche | | |
| Osman, Dorothy M. | 18 SEP 1913 | 05 JAN 2009 |
| Osman, Golla | | |
| Osman, Guy | | |
| Osman, Henry | | |
| Osman, James | | |
| Osman, James | | |
| Osman, Kathryn | | |
| Osman, Robert | | |
| Osmond, Mary | | |
| Osterhout, Katie Marie | 12 OCT 1984 | |
| Osterhout, Mahlon | | |
| Ostlund, Charles William | | |
| Oswald, Daniel | | |
| Oswald, Elizabeth | | |
| Oswald, Magdalena | | |
| Oswald, Magdalena \"Mollie\" | | |
| Oswald, Maria Barbara | JUL 1731 | ABT 1816 |
| Oswalt, J. | | |
| Oswalt, Sarah | | |
| Oswalt, __ | | |
| Ott, Elizabeth E. | | |
| Ott, Lisa Eileen | 3 SEP 1961 | |
| Ott, Richard L. | | |
| Ottaway, Brent Michael | 1961 | |
| Ottaway, Kurt Nicholas | 1959 | |
| Ottaway, Merle | | |
| Otto, Clara Bertha | | |
| Otto, Conrad | | |
| Overdorf, Denia | | 1911 |
| Overdorf, Hilda J. | | |
| Overmyer, John George | | |
| Overmyer, Magdalena | 02 AUG 1767 | |
| Owen, Barbara Elizabeth | 28 SEP 1853 | 07 MAY 1919 |
| Owen, Caroline | | |
| Owen, Clarence | NOV 1892 | |
| Owen, Clarence Almond | | |
| Owen, Hannah | 1855 | |
| Owen, Jewel | MAY 1861 | |
| Owen, John D. | 7 AUG 1921 | |
| Owen, Joseph | 1862 | |
| Owen, Lowry | | |
| Owen, Martin | | |
| Owen, Minard P. | 1867 | |
| Owen, Seeley | DEC 1884 | |
| Owen, Seeley | 1857 | |
| Owen, Seeley | 20 MAR 1805 | 1881 |
| Owen, T. G. | | 1892 |
| Owens, Alice Amelia | 28 AUG 1902 | 15 MAY 1993 |
| Owens, Edna Earl | 29 NOV 1913 | 25 AUG 2000 |
| Owens, Joseph H. | 20 SEP 1898 | |
| Owens, Shirley | | |
| Owens, Virginia | | |
| Owens, __ | | |
| Ozpar, Deborah Ann | 8 MAY 1959 | 1963 |
| Ozpar, Donald E. | 16 NOV 1928 | |
| Ozpar, Donald Eugene | 23 NOV 1955 | |
| Ozpar, Douglas Edward | 13 MAR 1965 | |
| Ozpar, Kathlene Marie | 25 NOV 1962 | |
| O\'Banion, Della Eva | 1893 | 29 JAN 1948 |
| O\'Banion, Joseph | | |
| O\'Barr, Virginia Mae | 7 DEC 1921 | JUN 1996 |
| O\'Connor, Walter F. | 1874 | 1946 |
| O\'Neil, William | | |