| Town / County |
Town / County |
Town / County |
| O'Brien / O'Brien |
O'Leary / Plymouth |
O'Neill / Dubuque |
| Oak / Marion |
Oak Grove / Linn |
Oak Point / Van Buren |
| Oak Spring / Davis |
Oakdale / Johnson |
Oakfield / Audubon |
| Oakgrove / Poweshiek |
Oakland / Clarke |
Oakland / Delaware |
| Oakland / Dubuque |
Oakland / Franklin |
Oakland / Louisa |
| Oakland / Pottawattamie |
Oakland / Van Buren |
Oakland Acres / Jasper |
| Oakland Mills / Henry |
Oakland Valley / Franklin |
Oakley / Lucas |
| Oaks / Appanoose |
Oakton / Scott |
Oakvale / Worth |
| Oakville / Louisa |
Oakwood / Floyd |
Oakwood / Polk |
| Oakwood / Tama |
Oasis / Johnson |
Ocheyedan / Osceola |
| Odd / Woodbury |
Odebolt / Sac |
Odessa / Louisa |
| Oelwein / Fayette |
Ogden / Boone |
Ogden / Dubuque |
| Ohio / Madison |
Ohio / Marion |
Ojedo / Harrison |
| Okoboji / Dickinson |
Ola / Lucas |
Ola / Tama |
| Olaf / Wright |
Olavet / Mahaska |
Old Mission / Winneshiek |
| Old Saint Johns / Harrison |
Old Town / Dickinson |
Old Town / Palo Alto |
| Oldfield / Polk |
Olds / Henry |
Olean / Keokuk |
| Olin / Jones |
Olio / Union |
Oliver / Sac |
| Olivet / Mahaska |
Olivet / Union |
Ollie / Keokuk |
| Olmitz / Lucas |
Olmstead / Harrison |
Olympus / Harrison |
| Onawa / Monona |
Onawa City / Monona |
Oneida / Delaware |
| Oneska / Mahaska |
Onion Grove / Cedar |
Ononwa / Louisa |
| Onslow / Jones |
Ontario / Story |
Opposition / Wapello |
| Oradell / Marion |
Oralabor / Polk |
Oran / Fayette |
| Orange / Clinton |
Orange City / Sioux |
Orchard / Mitchell |
| Ord / Madison |
Orford / Tama |
Orient / Adair |
| Orillia / Warren |
Orion / Fayette |
Orlando / Wayne |
| Orleans / Appanoose |
Orleans / Dickinson |
Orleans / Winneshiek |
| Ormanville / Wapello |
Ornbaum / Mahaska |
Oro / Montgomery |
| Orono / Muscatine |
Orrin Glen / Delaware |
Orrinden / Delaware |
| Orrville / Keokuk |
Orrville / Mitchell |
Orsland / Buena Vista |
| Orson / Harrison |
Orton / Harrison |
Ortonville / Dallas |
| Orville / Appanoose |
Orville / Keokuk |
Osage / Mitchell |
| Osage / Fremont |
Osborn / Howard |
Osborne / Clayton |
| Osceola / Clarke |
Osgood / Palo Alto |
Oshkosh / Sioux |
| Oskaloosa / Mahaska |
Oskaloosa Junction / Mahaska |
Osprey / Dallas |
| Osprey / Monroe |
Ossian / Winneshiek |
Osterdock / Clayton |
| Oswalt / Jasper |
Oswego / Warren |
Otero / Jefferson |
| Otho / Webster |
Otho (P.O.) / Webster |
Otis / Linn |
| Otisville / Franklin |
Otisville / Wright |
Otley / Marion |
| Oto / Woodbury |
Otranto / Mitchell |
Otsego / Fayette |
| Otsego / Wright |
Ottawa / Black Hawk |
Ottawa / Clarke |
| Ottawa / Polk |
Ottawa City / Poweshiek |
Otter Creek / Crawford |
| Otter Creek / Jackson |
Otter Creek / Linn |
Otter Creek / Tama |
| Otterville / Buchanan |
Otto / Woodbury |
Ottosen / Humboldt |
| Ottumwa / Wapello |
Ottumwa Junction / Wapello |
Overmans Ferry / Muscatine |
| Overton / Lee |
Ovid / Taylor |
Ovid / Wayne |
| Owasa / Hardin |
Owego / Woodbury |
Owen / Cerro Gordo |
| Owen's Grove / Cerro Gordo |
Owlake / Humboldt |
Oxford / Johnson |
| Oxford / Mahaska |
Oxford Junction / Jones |
Oxford Mills / Jones |
| Oyens / Plymouth |
Ozark / Jackson |
