| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
|---|
| O'Bryonsville | city | Ohio | United States | 39.13222 | -84.46111 | 695 | 232028 |
| O'Connor Point | city | Ohio | United States | 40.49667 | -83.85222 | 997 | 7686 |
| Oak | city | Ohio | United States | 39.74111 | -80.93972 | 1197 | 1676 |
| Oak Grove | city | Ohio | United States | 39.44861 | -81.46667 | 600 | 20046 |
| Oak Harbor | city | Ohio | United States | 41.50667 | -83.14667 | 587 | 5770 |
| Oak Hill | city | Ohio | United States | 38.89389 | -82.57361 | 797 | 1985 |
| Oak Hill | city | Ohio | United States | 40.41417 | -82.24111 | 997 | 1682 |
| Oak Hill Village subdivision | city | Ohio | United States | 41.65694 | -81.4 | 603 | 70800 |
| Oak Knoll | city | Ohio | United States | 40.56111 | -83.14583 | 997 | 39357 |
| Oak Meadows | city | Ohio | United States | 41.53528 | -83.59528 | 646 | 25616 |
| Oak Meadows subdivision | city | Ohio | United States | 41.4575 | -84.59528 | 797 | 6350 |
| Oak Park | city | Ohio | United States | 39.61389 | -82.89417 | 810 | 16479 |
| Oak Park | city | Ohio | United States | 40.25167 | -80.99889 | 1099 | 4081 |
| Oak Ridge | city | Ohio | United States | 39.65833 | -84.1375 | 997 | 87869 |
| Oak Ridge | city | Ohio | United States | 40.83972 | -81.50472 | 1095 | 47550 |
| Oakcrest subdivision | city | Ohio | United States | 39.94722 | -83.77111 | 1000 | 69584 |
| Oakdale | city | Ohio | United States | 39.21111 | -84.60583 | 898 | 96502 |
| Oakdale | city | Ohio | United States | 39.69083 | -84.13417 | 997 | 135274 |
| Oakdale | city | Ohio | United States | 39.52167 | -82.09417 | 721 | 5301 |
| Oakdale historical | city | Ohio | United States | 41.13278 | -83.95778 | 741 | 2838 |
| Oakfield | city | Ohio | United States | 39.65917 | -82.11611 | 898 | 2261 |
| Oakfield | city | Ohio | United States | 41.40889 | -80.85 | 921 | 4194 |
| Oakgrove | city | Ohio | United States | 39.85167 | -83.88917 | 980 | 14811 |
| Oakgrove | city | Ohio | United States | 40.14056 | -81.22861 | 1197 | 1491 |
| Oakgrove historical | city | Ohio | United States | 38.99139 | -81.90806 | 698 | 2819 |
| Oakland | city | Ohio | United States | 39.74444 | -84.14333 | 898 | 163131 |
| Oakland | city | Ohio | United States | 39.48278 | -83.91278 | 997 | 5130 |
| Oakland | city | Ohio | United States | 40.05139 | -82.7775 | 1066 | 9132 |
| Oakland | city | Ohio | United States | 39.59833 | -82.75667 | 1023 | 3603 |
| Oakland | city | Ohio | United States | 39.08417 | -82.71306 | 800 | 2360 |
| Oakland historical | city | Ohio | United States | 39.94028 | -81.97833 | 800 | 31592 |
| Oakland subdivision | city | Ohio | United States | 39.50667 | -84.40028 | 744 | 61373 |
| Oakland subdivision | city | Ohio | United States | 39.46222 | -84.34889 | 715 | 54690 |
| Oakley | city | Ohio | United States | 39.15361 | -84.425 | 600 | 189736 |
| Oakley Square | city | Ohio | United States | 39.15111 | -84.43361 | 600 | 189736 |
| Oakmont | city | Ohio | United States | 41.54167 | -83.59722 | 639 | 61678 |
| Oakpoint historical | city | Ohio | United States | 41.43556 | -82.24861 | 597 | 50774 |
| Oakshade | city | Ohio | United States | 41.66889 | -84.15222 | 797 | 2240 |
| Oakthorpe | city | Ohio | United States | 39.80556 | -82.43611 | 912 | 3917 |
| Oakview | city | Ohio | United States | 40.69389 | -84.21028 | 846 | 6861 |
| Oakwood | city | Ohio | United States | 41.09556 | -84.38056 | 698 | 1684 |
| Oakwood | city | Ohio | United States | 39.72528 | -84.17417 | 997 | 167390 |
| Oakwood | city | Ohio | United States | 41.36528 | -81.50806 | 1043 | 54736 |
| Oakwood Park subdivision | city | Ohio | United States | 39.43278 | -81.45028 | 787 | 21957 |
| Oakwood Village subdivision | city | Ohio | United States | 39.96722 | -83.77889 | 997 | 43225 |
| Oakwood subdivision | city | Ohio | United States | 39.98306 | -81.56 | 800 | 14430 |
| Obad historical | city | Ohio | United States | 38.9625 | -82.37472 | 669 | 2044 |
| Oberlin | city | Ohio | United States | 41.29389 | -82.2175 | 797 | 12949 |
| Oberlin Beach | city | Ohio | United States | 41.38278 | -82.50778 | 593 | 6121 |
| Obetz | city | Ohio | United States | 39.87889 | -82.95083 | 705 | 95793 |
| Oceola | city | Ohio | United States | 40.84472 | -83.09389 | 898 | 1427 |
| Oco | city | Ohio | United States | 40.10972 | -80.99778 | 1122 | 4070 |
| Oconorville historical | city | Ohio | United States | 39.65917 | -82.15889 | 898 | 2986 |
| Octa | city | Ohio | United States | 39.60389 | -83.61306 | 997 | 1834 |
| Odbert historical | city | Ohio | United States | 40.48083 | -81.48639 | 997 | 20196 |
| Odell | city | Ohio | United States | 40.15083 | -81.47694 | 898 | 1362 |
| Ogden | city | Ohio | United States | 39.43083 | -83.91139 | 987 | 6571 |
| Ogles historical | city | Ohio | United States | 39.54056 | -83.83167 | 997 | 3621 |
| Ogleton historical | city | Ohio | United States | 39.47111 | -84.73806 | 898 | 25769 |
| Ogontz | city | Ohio | United States | 41.34389 | -82.45944 | 770 | 4430 |
| Ohio City | city | Ohio | United States | 40.77139 | -84.61556 | 797 | 1733 |
| Ohio City | city | Ohio | United States | 41.48417 | -81.71139 | 659 | 189956 |
| Ohio Furnace | city | Ohio | United States | 38.60278 | -82.78472 | 725 | 5069 |
| Ohlton historical | city | Ohio | United States | 41.12167 | -80.78028 | 1026 | 41361 |
| Ohltown | city | Ohio | United States | 41.12833 | -80.78528 | 1026 | 46109 |
| Ohmer Park subdivision | city | Ohio | United States | 39.74167 | -84.15222 | 928 | 163131 |
| Oil Center historical | city | Ohio | United States | 41.21111 | -83.645 | 711 | 3787 |
| Oil Station | city | Ohio | United States | 41.25611 | -83.01194 | 741 | 7564 |
| Okeana | city | Ohio | United States | 39.34778 | -84.7675 | 770 | 5965 |
| Okey | city | Ohio | United States | 38.62917 | -82.36833 | 898 | 1954 |
| Oklahoma historical | city | Ohio | United States | 39.78639 | -84.63389 | 1000 | 9557 |
| Okolona | city | Ohio | United States | 41.35528 | -84.21778 | 698 | 2353 |
| Olbers | city | Ohio | United States | 39.48278 | -82.11 | 879 | 5964 |
| Old Fort | city | Ohio | United States | 41.24 | -83.15 | 649 | 2348 |
| Old Gore | city | Ohio | United States | 39.5775 | -82.305 | 800 | 3553 |
| Old Pimtown historical | city | Ohio | United States | 40.24 | -83.75861 | 1079 | 2704 |
| Old Town | city | Ohio | United States | 40.4425 | -81.46333 | 898 | 10457 |
| Old Washington | city | Ohio | United States | 40.03861 | -81.44472 | 1007 | 2490 |
| Olde West Chester | city | Ohio | United States | 39.33167 | -84.40722 | 698 | 59007 |
| Oldham | city | Ohio | United States | 40.07083 | -81.59917 | 931 | 13243 |
| Oldtown | city | Ohio | United States | 39.73028 | -83.93778 | 885 | 23027 |
| Oldtown Flats | city | Ohio | United States | 38.99667 | -81.8425 | 711 | 2284 |
| Olena | city | Ohio | United States | 41.15444 | -82.54111 | 941 | 2206 |
| Olentangy | city | Ohio | United States | 40.06306 | -83.04639 | 800 | 148387 |
| Olentangy | city | Ohio | United States | 40.76167 | -82.87361 | 1043 | 6280 |
| Olentangy High Bluffs subdivision | city | Ohio | United States | 40.1325 | -83.02417 | 898 | 56780 |
| Olive Branch | city | Ohio | United States | 39.08389 | -84.22528 | 800 | 32612 |
| Olive Furnace | city | Ohio | United States | 38.76167 | -82.63 | 846 | 1512 |
| Olive Green | city | Ohio | United States | 40.31917 | -82.83028 | 1089 | 3845 |
| Olive Green | city | Ohio | United States | 39.74389 | -81.615 | 1000 | 1128 |
| Olivesburg | city | Ohio | United States | 40.88583 | -82.42889 | 1115 | 4992 |
| Olivett | city | Ohio | United States | 40.02194 | -81.13806 | 1197 | 3655 |
| Ollins Corners | city | Ohio | United States | 41.79944 | -80.66944 | 908 | 3511 |
| Olmsted | city | Ohio | United States | 41.40694 | -81.89694 | 705 | 87573 |
| Olmsted Falls | city | Ohio | United States | 41.375 | -81.90833 | 751 | 56314 |
| Olszeski Town | city | Ohio | United States | 40.19444 | -80.78889 | 898 | 5812 |
| Olympia historical | city | Ohio | United States | 39.54111 | -83.37778 | 912 | 11734 |
| Olympic Hills subdivision | city | Ohio | United States | 39.94889 | -83.78806 | 997 | 69584 |
| Omar | city | Ohio | United States | 41.12417 | -82.87139 | 898 | 2198 |
| Omega | city | Ohio | United States | 39.15167 | -82.91028 | 583 | 4374 |
| Oneida | city | Ohio | United States | 39.47833 | -84.39028 | 705 | 58193 |
| Oneida | city | Ohio | United States | 40.69861 | -81.14917 | 1092 | 7184 |
| Ontario | city | Ohio | United States | 40.75944 | -82.59028 | 1377 | 20068 |
| Opera historical | city | Ohio | United States | 39.90944 | -82.16278 | 997 | 3140 |
| Opperman | city | Ohio | United States | 39.89056 | -81.60083 | 997 | 3388 |
| Oran | city | Ohio | United States | 40.29111 | -84.32167 | 974 | 3227 |
| Orange | city | Ohio | United States | 40.17417 | -83.00806 | 931 | 15862 |
| Orange | city | Ohio | United States | 40.28806 | -81.68306 | 849 | 3889 |
| Orange | city | Ohio | United States | 41.44972 | -81.48083 | 1181 | 69248 |
| Orange Center | city | Ohio | United States | 41.46194 | -81.43833 | 1030 | 49634 |
| Orangeburg historical | city | Ohio | United States | 39.83861 | -84.74694 | 1190 | 3904 |
| Orangeville | city | Ohio | United States | 41.33917 | -80.51917 | 928 | 4374 |
| Orbiston | city | Ohio | United States | 39.48556 | -82.16861 | 790 | 5171 |
| Orchard Acres subdivision | city | Ohio | United States | 40.86389 | -81.41667 | 1095 | 84256 |
| Orchard Beach | city | Ohio | United States | 41.40639 | -82.40944 | 597 | 10811 |
| Orchard Grove subdivision | city | Ohio | United States | 41.71167 | -81.26444 | 685 | 47969 |
| Orchard Heights subdivision | city | Ohio | United States | 40.77111 | -81.34806 | 1099 | 71560 |
| Orchard Hill subdivision | city | Ohio | United States | 38.81389 | -82.21167 | 534 | 9578 |
| Orchard Island | city | Ohio | United States | 40.47972 | -83.88528 | 987 | 8501 |
| Orchard View | city | Ohio | United States | 41.59583 | -83.42417 | 610 | 21469 |
| Oregon | city | Ohio | United States | 41.64361 | -83.48694 | 606 | 79274 |
| Oregon Corners | city | Ohio | United States | 41.16639 | -81.405 | 1049 | 65957 |
| Oregonia | city | Ohio | United States | 39.45083 | -84.09611 | 800 | 5020 |
| Oreton | city | Ohio | United States | 39.16389 | -82.41278 | 698 | 1234 |
| Oreville | city | Ohio | United States | 39.58472 | -82.26889 | 875 | 2451 |
| Orient | city | Ohio | United States | 39.80278 | -83.15194 | 800 | 12435 |
| Orland | city | Ohio | United States | 39.38278 | -82.42389 | 872 | 1164 |
| Orpheus | city | Ohio | United States | 38.96306 | -82.45833 | 807 | 1935 |
| Orrville | city | Ohio | United States | 40.84361 | -81.76417 | 1066 | 13518 |
| Orwell | city | Ohio | United States | 41.535 | -80.86833 | 902 | 2816 |
| Osage | city | Ohio | United States | 40.47444 | -80.72222 | 1102 | 4850 |
| Osborn Corners | city | Ohio | United States | 41.20167 | -81.67889 | 1013 | 11959 |
| Osceola | city | Ohio | United States | 39.34167 | -84.05528 | 797 | 4617 |
| Osgood | city | Ohio | United States | 40.33972 | -84.49528 | 948 | 3256 |
| Ostrander | city | Ohio | United States | 40.26611 | -83.21278 | 898 | 3388 |
| Otho historical | city | Ohio | United States | 39.68111 | -81.69778 | 800 | 915 |
| Otsego | city | Ohio | United States | 41.4475 | -83.77917 | 643 | 6308 |
| Otsego | city | Ohio | United States | 40.12139 | -81.765 | 797 | 1348 |
| Ottawa | city | Ohio | United States | 41.01917 | -84.04722 | 708 | 7791 |
| Ottawa Hills | city | Ohio | United States | 41.66417 | -83.64333 | 600 | 131401 |
| Otter | city | Ohio | United States | 40.27583 | -83.41917 | 997 | 5187 |
| Otterbein | city | Ohio | United States | 39.94583 | -84.67167 | 1099 | 3108 |
| Otterbein | city | Ohio | United States | 39.44611 | -84.27806 | 898 | 17761 |
| Otterbein | city | Ohio | United States | 40.58417 | -83.50556 | 997 | 1777 |
| Ottokee | city | Ohio | United States | 41.60222 | -84.13444 | 751 | 6294 |
| Ottokee Station | city | Ohio | United States | 41.59972 | -84.155 | 767 | 6294 |
| Ottoville | city | Ohio | United States | 40.93222 | -84.33889 | 738 | 2456 |
| Otway | city | Ohio | United States | 38.86639 | -83.1875 | 800 | 2067 |
| Outville | city | Ohio | United States | 39.995 | -82.59583 | 1013 | 7690 |
| Oval City | city | Ohio | United States | 40.89583 | -81.3275 | 1099 | 30461 |
| Over-The-Rhine | city | Ohio | United States | 39.11139 | -84.51528 | 541 | 239048 |
| Overlook Hills | city | Ohio | United States | 40.38361 | -80.69222 | 1013 | 20768 |
| Overpeck | city | Ohio | United States | 39.45083 | -84.51444 | 623 | 41367 |
| Overton | city | Ohio | United States | 40.86472 | -82.01028 | 918 | 6188 |
| Ovid | city | Ohio | United States | 40.04333 | -82.80917 | 997 | 16615 |
| Owens | city | Ohio | United States | 40.52028 | -83.15806 | 925 | 19682 |
| Owensville | city | Ohio | United States | 39.1225 | -84.13583 | 895 | 11117 |
| Owensville | city | Ohio | United States | 38.85111 | -83.04028 | 600 | 4825 |
| Owl Town historical | city | Ohio | United States | 40.00694 | -83.82167 | 980 | 12448 |
| Owls Town historical | city | Ohio | United States | 40.35972 | -82.15722 | 1010 | 927 |
| Oxford | city | Ohio | United States | 39.50694 | -84.74528 | 898 | 25503 |
| Oxtoby historical | city | Ohio | United States | 39.90167 | -83.69556 | 1099 | 5413 |
| Ozark | city | Ohio | United States | 39.82667 | -81.08194 | 1197 | 1838 |