| Name | Township | No. | Land location | Image |
|---|
| Oakes, John | Sparta | 367 | |  |
| Obenhaltzer, Jacob | Swan | | Section 16, T33, R11 (80 ac.) | |
| Obenhaltzer, Jacob | Swan | | Section 15, T33, R11 (40 ac.) | |
| Ockerman, John | Wayne | 568 | Section 13, T35, R11 (40 ac.) | |
| Odell, Charles | Green | 253 | Section 16, T33, R10 (40 ac.) | |
| Officer, Mary | Washington | 326 | Section 12, T33, R8 (80 ac.) | |
| Officer, Robert | Noble | 391 | | |
| Officer, Robert | Washington | 328 | | |
| Ogden, Aaron | Perry | 776 | Section 27, T35, R8 (75.5 ac.) | |
| Ogden, Aaron | Perry | 777 | Section 27, T35, R8 (11 ac.) | |
| Ogden, Aaron | Perry | 778 | In-lot 22, Ligonier | |
| Ogden, Aaron | Washington | 325 | Section 13, T33, R8 (160 ac.) | |
| Ogden, Ira | Washington | 329 | | |
| Ohdendahl, William | Perry | 784 | | |
| Ohlwine & Keller | Perry | 781 | Section 7, T35, R8 (56.82 ac.) | |
| Ohlwine & Smith | Perry | 779 | In-lot 99, Ligonier | |
| Ohlwine, C. W. | Sparta | 366 | | |
| Ohlwine, Daniel | Sparta | 364 | Section 34, T34, R8 (124.92 ac.) | |
| Ohlwine, J. S. | Perry | 783 | | |
| Ohlwine, Samuel | Perry | 780 | In-lot 32, Ligonier | |
| Ohlwine, Samuel | Sparta | 361 | Section 33, T34, R8 (80 ac.) | |
| Ohlwine, Samuel | Sparta | 362 | Section 34, T34, R8 (29 ac.) | |
| Ohlwine, Samuel | Sparta | 363 | Section 27, T34, R8 (1 ac.) | |
| Olgle, Joseph | Jefferson | 273½ | Section 23, T34, R10 (80 ac.) | |
| Olgle, Joseph | Jefferson | 274½ | Section 23, T34, R10 (40 ac.) | |
| Oliger, John | Jefferson | 273 | Section 31, T34, R10 (176 ac.) | |
| Olin, Ezra A. | Orange | 527 | Section 10, T35, R10 (30 ac.) | |
| Olinger, John | Green | 250 | Section 6, T33, R10 (158 ac.) | |
| Olinger, John | Green | 252 | Section 6, T33, R10 (160 ac.) | |
| Olinger, Joseph | Noble | 390 | Section 36, T33, R9 (160 ac.) | |
| Oliver, George | York | 434 | | |
| Oliver, James | Wayne | 567 | Section 1, T35, R11 (49.3 ac.) | |
| Oliver, Joshua C. | York | 430 | Section 30, T34, R9 (80 ac.) | |
| Oliver, Joshua C. | York | 431 | Section 29, T34, R9 (80 ac.) | |
| Oliver, Margaret | York | 436 | In-lot 14, Port Mitchell | |
| Olp, John (heirs) | Jefferson | 269 | Section 8, T34, R10 (80 ac.) | |
| Oneal, Conelius | Wayne | 572 | | |
| Orr, A. J. | Wayne | 569 | Section 10, T35, R11 (80 ac.) | |
| Orr, Ephraim | York | 433 | | |
| Orr, Jackson | Noble | 389 | Section 28, T33, R9 (80 ac.) | |
| Orr, Samuel | Washington | 327 | Section 14, T33, R8 (160 ac.) | |
| Orr, Thomas | Wayne | 570 | Section 27, T35, R11 (108 ac.) | |
| Orr, Thomas J. | Wayne | 571 | | |
| Ortlieb, Jacob | Sparta | 365 | Section 31, T34, R8 (69 ac.) | |
| Orton, James | Wayne | 561 | Section 8, T35, R11 (105.75 ac.) | |
| Orton, James | Wayne | 562 | Section 8, T35, R11 | |
| Orton, James R. | Wayne | 562 | Section 8, T35, R11 (40 ac.) | |
| Orton, James R. | Wayne | 564 | Section 8, T35, R11 (80 ac.) | |
| Osborn, Charles | Green | 241 | Section 15, T33, R10 (80 ac.) | |
| Osborn, David C. | Orange | 528 | Section 20, T35, R10 (40 ac.) | |
| Osborn, David C. | Orange | 529 | Section 29, T35, R10 (40 ac.) | |
| Osborn, David C. | Orange | 530 | Section 29, T35, R10 (20 ac.) | |
| Osborn, Horace | Wayne | 566 | Section 29, T35, R11 (40 ac.) | |
| Osborn, J. B. | Wayne | | | |
| Otman, Jacob | Wayne | | | |
| Ott, Abraham | Noble | 376 | Section 26, T33, R9 (160 ac.) | |
| Ott, Abraham | Noble | 377 | Section 13, T33, R9 (40 ac.) | |
| Ott, Abraham | Noble | 388 | Section 26, T33, R9 (160 ac.) | |
| Ott, George | Green | 242 | Section 29, T33, R10 (160 ac.) | |
| Ott, George | Green | 243 | Section 20, T33, R10 (40 ac.) | |
| Ott, George | Green | 245 | Section 20, T33, R10 (160 ac.) | |
| Ott, George | Noble | 374 | Section 25, T33, R9 (8 ac.) | |
| Ott, George | Noble | 375 | Section 244, T33, R9 (80 ac.) | |
| Ott, Jacob | Perry | 774 | Section 18, T35, R8 (74.66 ac.) | |
| Ott, Jacob | Perry | 775 | Section 18, T35, R8 (152.64 ac.) | |
| Ott, Jesse | Green | 248 | Section 29, T33, R10 (160 ac.) | |
| Ott, Jesse | Green | 249 | Section 30, T33, R10 (40 ac.) | |
| Ott, John | Green | 244 | Section 29, T33, R10 (160 ac.) | |
| Ott, John | Green | 246 | Section 18, T33, R10 (160 ac.) | |
| Ott, John | Green | 247 | Section 32, T33, R10 (82 ac.) | |
| Ott, John | Green | 251 | Section 19, T33, R10 (160 ac.) | |
| Ott, John | Perry | 785 | | |
| Ott, Michael | Perry | 782 | | |
| Ottman, Jacob | Allen | 378 | | |
| Overly, John | Jefferson | 270 | Section 14, T34, R10 (80 ac.) | |
| Owen, Davis | Jefferson | 272 | Section 11, T34, R10 (80 ac.) | |
| Owen, Edward | Wayne | 565 | Section 31, T35, R11 (160 ac.) | |
| Owen, Elezer | Orange | 524 | Section 35, T35, R10 (80 ac.) | |
| Owen, G. S. | Green | 240 | Section 12, T33, R10 (10 ac.) | |
| Owen, Gideon S. | York | 435 | | |
| Owen, H. V. | York | 432 | Section 26, T34, R9 (160 ac.) | |
| Owen, Ira | Orange | 526 | Section 35, T35, R10 (80 ac.) | |
| Owen, Isaiah | Orange | 522 | Section 26, T35, R10 (20 ac.) | |
| Owen, Isaiah | Orange | 523 | Section 36, T35, R10 (80 ac.) | |
| Owen, Mary | Orange | 525 | Section 35, T35, R10 (80 ac.) | |
| Owen, Moses | Jefferson | 271 | Section 27, T34, R10 (40 ac.) | |
| Owens, Owen | Allen | 379 | Section 6, T34, R11 (80 ac.) | |
