| Oats, W.L. | Crawford, Mamie F. | Aug. 21, 1911 | D-81 | 1087 | ||
| * | O'Bryan, John B.O. | Tom, Mrs. Sarah J. | Aug. 14, 1889 | A-100 | no # | |
| Ochoa, Pedro | Pecino, Francisco | Dec. 23, 1925 | F-263 | |||
| Ogden, H.B. | Crothers, Carrie C. | Oct. 6, 1914 | D-164 | 1517 | Anna Lu | |
| Ogden, John Henry | Landers, Laura | Aug. 30, 1915 | E-74 | |||
| Ogden, Roy C. | Rudolph, Pauline | Feb. 16, 1936 | G-449 | |||
| Ogden, W.A. | Horn, Mollie R. | June 24, 1918 | E-267 | 2080 | Anna Lu | |
| Ogle, H.W. | Worrell, Emma | May 11, 1893 | A-172 | no # | Donald Fleming | |
| Ohlhausen, Robert | Whiteley, Bettie | Apr. 18, 1909 | C-207 | |||
| * | Oldham, C.H. | Henderson, Mattie | Sept. 17, 1879 | A-3 | no # | |
| Oldham, Carl | Eklund, Lillian | May 8, 1920 | E-387 | 2331 | ||
| Oldham, John | Carson, Cathryn | Feb. 12, 1933 | G-178 | |||
| Oldham, Travis | Landrum, Christine | Feb. 2, 1929 | F-547 | 4002 | ||
| Oliver, C.W.D. | James, Willie B. | May 17, 1924 | F-116 | |||
| Oliver, P.L. | Banks, Ophelia | July 11, 1937 | G-573 | |||
| * | Oliver, Percy L. | Hays, Mrs. Ollie | June 29, 1935 | G-388 | 4951 | |
| Olivo, Martin | Delgado, Yrene | Sept. 22, 1924 | F-138 | |||
| * | Olliver, E.H,. | Davis, Laura | Oct. 25, 1889 | A1-105 | no # | |
| Olsien, E. Conrad | Swensk, Roas E. | July 19, 1930 | G-28 | |||
| Orlopp, Paul Threadway | Souther, Ollie | Nov. 12, 1912 | D-164 | 1261 | Anna Lu | |
| Ormsby, G.A. | Freeman, N.J. | Aug. 13, 1889 | A-100 | |||
| Ormsby, G.A. | Mason, L.M. | Nov. 12, 1893 | A-179 | |||
| Orrick, Cecil Pat | Carroll, Beulah | Nov. 5, 1930 | G-41 | |||
| Ortega, Margarito | Ambiz, Maria | Apr. 21, 1928 | F-457 | |||
| Ortegan, Frank | Gauna, Celia | Nov. 13, 1925 | F-247 | |||
| Ortegon, Victor | Facio, Dionicia | Sept. 27, 1924 | F-140 | |||
| * | Ortez, Arunlfo | Domingues, Fuanita | Oct. 2, 1912 | D-156 | 1245 | |
| * | Ortez, Clemente | Salaiz, Petra | Aug. 9, 1925 | F-217 | 3222 | |
| Ortiz, Adolpho | Mejia, Manuela | Nov. 3, 1935 | G-417 | |||
| Ortiz, Gregorio L. | Gutierrez, Maria | Dec. 20, 1919 | E-341 | |||
| Ortiz, Nolberto L. | Menchaca, Antonia | Aug. 13, 1926 | F-303 | |||
| Osburn, Milton | Shuffield, Mauriel | Apr. 17, 1929 | F-563 | |||
| Otte, August H. | Carter, Elmira Catherine | Oct. 15, 1895 | A-204 | no # | ||
| Otte, Ernest K. | Wilder, Ivyll Kathryn | Dec. 22, 1934 | G-352 | |||
| Otte, F.W. | Hofmann, Mary L. | Apr. 23, 1906 | C-20 | 354 | ||
| * | Otte, Fritz | Butler, Mary | June 11, 1922 | E-573 | 2702 | |
| Otte, H.A. | Gross, Louise | Sept. 8, 1909 | C-224 | Ida Sears 11-26-56 | ||
| Otte, J.W.F. | Region, Lillie | Apr. 15, 1933 | G-194 | 4563 | ||
| * | Owen, J.M. | McMair, Lucy | Aug. 2, 1914 | D-280 | 1495 | |
| Owens, Geo. W. | Patterson, Ruth | Jan. 29, 1919 | E-286 | |||
| Owens, Henry | Wolfrum, Ida Jewell | Oct. 4, 1930 | G-36 | |||
| Owens, J.F. | Hargrove, Eva | Jan. 15, 1901 | B-35 | |||
| * | Owens, J.F. | Hargrove, Eva | permit | permit | ||
| Owens, Jesse | Baze, Hettie | Sept. 27, 1930 | G-37 | |||
| Owens, Robert Benton | Crumbley, Sarah | Dec. 18, 1906 | C-52 | |||
| Owens, Tom | Schooley, Mary E. | Mar. 14, 1906 | C-13 | 347 | Charlotte, McDonald | |
| Oyas, Josede | Sandoval, Carlota | Mar. 22, 1925 | F-186 | |||
| Ozuna, Guadalupe | Rosales, Mrs. Luvenia | Jan. 3, 1927 | F-345 |