| The Pottawattamie County Genealogical Society has access to at least one biography for the following early residents of Pottawattamie County. | ||||
| Index | ||||
| Note: Except for Council Bluffs, all references in the second column are to a township. | ||||
| Olney, Justin J. | Belknap |
| Orr, William | Keg Creek |
| Osborn, James W. | Hazel Dell |
| Osborne, F. J. | Council Bluffs |
| Otto, G. B. | Grove |
| Ouren, H. | Silver Creek |