Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Monfort Heights Elementary School | School | 281 | Hamilton | 39 11 19 N | 084 36 16 W |
| Monfort Heights Shopping Center | Locale | 283 | Hamilton | 39 11 30 N | 084 35 53 W |
| Monfort Heights United Methodist Church | Church | 285 | Hamilton | 39 11 22 N | 084 36 17 W |
| Monitor Elementary School | School | 171 | Lawrence | 38 29 44 N | 082 38 45 W |
| Monkey Run | Stream | | Hocking | 39 32 59 N | 082 20 54 W |
| Monkey Run | Stream | | Meigs | 39 01 12 N | 082 02 30 W |
| Monkey Run | Stream | | Van Wert | 40 54 41 N | 084 37 53 W |
| Monnett | Populated Place | 297 | Crawford | 40 43 03 N | 083 02 24 W |
| Monnett Cemetery | Cemetery | 238 | Pickaway | 39 28 34 N | 082 47 47 W |
| Monnett Chapel | Church | 308 | Crawford | 40 44 21 N | 082 59 36 W |
| Monnett Chapel Cemetery | Cemetery | 309 | Crawford | 40 44 21 N | 082 59 33 W |
| Monnett Post Office (historical) | Post Office | 297 | Crawford | 40 43 05 N | 083 02 25 W |
| Mononcue | Populated Place | 251 | Wyandot | 40 49 38 N | 083 16 07 W |
| Monroe | Populated Place | 254 | Butler | 39 26 25 N | 084 21 44 W |
| Monroe | Populated Place | 317 | Greene | 39 40 38 N | 083 51 54 W |
| Monroe | Populated Place | 210 | Jackson | 38 51 23 N | 082 37 45 W |
| Monroe Basin | Lake | 221 | Muskingum | 40 09 13 N | 081 57 44 W |
| Monroe Basin State Wildlife Area | Park | 220 | Muskingum | 40 09 12 N | 081 57 44 W |
| Monroe Bidwell Ditch | Canal | 294 | Madison | 39 58 57 N | 083 19 29 W |
| Monroe Cemetery | Cemetery | 261 | Ashtabula | 41 51 09 N | 080 36 38 W |
| Monroe Cemetery | Cemetery | 231 | Butler | 39 26 58 N | 084 21 27 W |
| Monroe Cemetery | Cemetery | 262 | Clermont | 38 58 06 N | 084 09 49 W |
| Monroe Cemetery | Cemetery | 376 | Coshocton | 40 27 03 N | 082 03 29 W |
| Monroe Cemetery | Cemetery | 208 | Cuyahoga | 41 28 40 N | 081 42 24 W |
| Monroe Cemetery | Cemetery | 246 | Jackson | 38 51 53 N | 082 37 47 W |
| Monroe Cemetery | Cemetery | 293 | Miami | 39 55 20 N | 084 15 13 W |
| Monroe Cemetery | Cemetery | 247 | Perry | 39 35 44 N | 082 07 11 W |
| Monroe Cemetery | Cemetery | 266 | Perry | 39 36 55 N | 082 04 52 W |
| Monroe Cemetery | Cemetery | 344 | Preble | 39 53 16 N | 084 39 23 W |
| Monroe Cemetery | Cemetery | 219 | Putnam | 41 07 23 N | 084 15 57 W |
| Monroe Cemetery | Cemetery | 205 | Scioto | 38 49 08 N | 082 48 49 W |
| Monroe Center | Populated Place | 278 | Ashtabula | 41 50 40 N | 080 34 17 W |
| Monroe Center Post Office (historical) | Post Office | 278 | Ashtabula | 41 50 40 N | 080 34 19 W |
| Monroe Chapel | Church | 229 | Jackson | 38 51 47 N | 082 37 55 W |
| Monroe Church (historical) | Church | 372 | Coshocton | 40 27 01 N | 082 03 29 W |
| Monroe County | Civil | 333 | Monroe | 39 44 00 N | 081 03 59 W |
| Monroe County Airport | Airport | 361 | Monroe | 39 46 44 N | 081 06 09 W |
| Monroe County Courthouse | Building | 367 | Monroe | 39 45 47 N | 081 06 58 W |
| Monroe County District Library | Building | 367 | Monroe | 39 45 39 N | 081 06 30 W |
| Monroe County Home | Building | 366 | Monroe | 39 46 36 N | 081 06 43 W |
| Monroe Creek | Stream | | Mercer | 40 30 39 N | 084 34 11 W |
| Monroe Elementary School | School | 252 | Butler | 39 26 35 N | 084 22 03 W |
| Monroe Elementary School | School | 205 | Butler | 39 23 16 N | 084 34 48 W |
| Monroe Elementary School | School | 275 | Clermont | 38 55 53 N | 084 12 15 W |
| Monroe Elementary School | School | 182 | Erie | 41 27 05 N | 082 42 15 W |
| Monroe Elementary School | School | 259 | Pickaway | 39 40 25 N | 083 10 38 W |
| Monroe Falls Metropolitan Park | Park | 327 | Summit | 41 07 45 N | 081 25 21 W |
| Monroe Hollow | Valley | | Jackson | 38 51 46 N | 082 37 33 W |
| Monroe Junior High School | School | 246 | Franklin | 39 58 27 N | 082 58 40 W |
| Monroe Lake | Reservoir | 328 | Monroe | 39 49 06 N | 081 08 17 W |
| Monroe Lake Dam | Dam | 328 | Monroe | 39 49 06 N | 081 08 17 W |
| Monroe Lake State Wildlife Area | Park | 373 | Monroe | 39 49 42 N | 081 08 50 W |
| Monroe Lutheran Cemetery | Cemetery | 366 | Holmes | 40 32 55 N | 081 59 36 W |
| Monroe Mall Shopping Center | Locale | 277 | Tuscarawas | 40 30 20 N | 081 27 29 W |
| Monroe Mills | Populated Place | 290 | Knox | 40 24 29 N | 082 22 09 W |
| Monroe Mills Post Office (historical) | Post Office | 290 | Knox | 40 24 30 N | 082 22 10 W |
| Monroe Post Office | Post Office | 252 | Butler | 39 26 25 N | 084 21 45 W |
| Monroe Presbyterian Church | Church | 333 | Summit | 41 05 57 N | 081 32 54 W |
| Monroe Rural High and Grade School (historical) | School | 243 | Muskingum | 40 07 04 N | 081 45 57 W |
| Monroe School | School | 275 | Ashtabula | 41 50 37 N | 080 34 36 W |
| Monroe School | School | 327 | Mahoning | 41 05 04 N | 080 40 04 W |
| Monroe School | School | 225 | Muskingum | 39 56 53 N | 081 59 57 W |
| Monroe School (historical) | School | 349 | Licking | 40 05 50 N | 082 44 53 W |
| Monroe School (historical) | School | 308 | Madison | 40 00 34 N | 083 25 03 W |
| Monroe Station (historical) | Locale | 204 | Butler | 39 27 03 N | 084 23 36 W |
| Monroe Street Church of God | Church | 252 | Miami | 40 02 23 N | 084 12 35 W |
| Monroe Street Market Square Shopping Center | Locale | 196 | Lucas | 41 42 09 N | 083 39 21 W |
| Monroe Street United Methodist Church | Church | 181 | Lucas | 41 40 14 N | 083 35 02 W |
| Monroe Township Building | Building | 251 | Miami | 39 57 39 N | 084 10 16 W |
| Monroe/Secor Park Shopping Center | Locale | 189 | Lucas | 41 41 04 N | 083 37 16 W |
| Monroefield | Populated Place | 376 | Monroe | 39 49 14 N | 081 12 08 W |
| Monroefield Post Office (historical) | Post Office | 378 | Monroe | 39 49 15 N | 081 12 09 W |
| Monroeville | Populated Place | 216 | Huron | 41 14 39 N | 082 41 47 W |
| Monroeville | Populated Place | 393 | Jefferson | 40 35 52 N | 080 50 15 W |
| Monroeville Cemetery | Cemetery | 399 | Jefferson | 40 35 53 N | 080 50 31 W |
| Monroeville Low Head Dam | Dam | 207 | Huron | 41 14 30 N | 082 41 42 W |
| Monroeville Low Head Reservoir | Reservoir | 207 | Huron | 41 14 30 N | 082 41 42 W |
| Monroeville Post Office | Post Office | 215 | Huron | 41 14 40 N | 082 41 45 W |
| Monroeville Public Library | Building | 214 | Huron | 41 14 37 N | 082 41 43 W |
| Montana (historical) | Populated Place | 221 | Putnam | 40 58 32 N | 084 20 09 W |
| Montana Avenue Church of the Nazarene | Church | 263 | Hamilton | 39 09 17 N | 084 34 48 W |
| Monterey | Populated Place | 275 | Clermont | 39 08 01 N | 084 04 53 W |
| Monterey | Populated Place | 257 | Hamilton | 39 06 42 N | 084 36 40 W |
| Monterey | Populated Place | 281 | Mercer | 40 27 02 N | 084 47 02 W |
| Monterey Cemetery | Cemetery | 261 | Clermont | 39 08 34 N | 084 05 12 W |
| Monterey Elementary School | School | 251 | Franklin | 39 53 08 N | 083 04 17 W |
| Monterey Heights (subdivision) | Populated Place | 332 | Stark | 40 50 15 N | 081 25 45 W |
| Monterey Post Office (historical) | Post Office | 275 | Clermont | 39 08 00 N | 084 04 55 W |
| Montezuma | Populated Place | 269 | Mercer | 40 29 20 N | 084 32 55 W |
| Montezuma Acres | Populated Place | 266 | Mercer | 40 30 07 N | 084 33 31 W |
| Montezuma Bay | Bay | 264 | Mercer | 40 30 13 N | 084 33 03 W |
| Montezuma Creek | Stream | | Mercer | 40 27 16 N | 084 33 26 W |
| Montezuma Post Office | Post Office | 269 | Mercer | 40 29 20 N | 084 32 55 W |
| Montfort Heights (subdivision) | Populated Place | 273 | Hamilton | 39 11 18 N | 084 35 43 W |
| Montgomery | Populated Place | 244 | Hamilton | 39 13 41 N | 084 21 15 W |
| Montgomery Cemetery | Cemetery | 390 | Jefferson | 40 28 39 N | 080 50 02 W |
| Montgomery Cemetery | Cemetery | 293 | Marion | 40 37 20 N | 083 24 31 W |
| Montgomery Cemetery | Cemetery | 348 | Morrow | 40 36 13 N | 082 50 26 W |
| Montgomery County | Civil | 308 | Montgomery | 39 45 01 N | 084 18 00 W |
| Montgomery County Childrens Home | Building | 255 | Montgomery | 39 47 46 N | 084 12 57 W |
| Montgomery County Home | Building | 275 | Montgomery | 39 44 07 N | 084 16 57 W |
| Montgomery County Memorial Hall | Building | 224 | Montgomery | 39 45 48 N | 084 11 23 W |
| Montgomery Elementary School | School | 301 | Ashland | 40 51 25 N | 082 15 53 W |
| Montgomery Elementary School | School | 244 | Hamilton | 39 13 50 N | 084 21 12 W |
| Montgomery Heights | Populated Place | 249 | Hamilton | 39 14 12 N | 084 21 25 W |
| Montgomery Methodist Episcopal Church (historical) | Church | 294 | Marion | 40 37 19 N | 083 24 33 W |
| Montgomery Park | Park | 238 | Hamilton | 39 14 25 N | 084 20 60 W |
| Montgomery Post Office (historical) | Post Office | 243 | Hamilton | 39 13 40 N | 084 21 15 W |
| Montgomery Square Shopping Center | Locale | 242 | Hamilton | 39 14 15 N | 084 21 03 W |
| Montgomery Township House | Building | 214 | Wood | 41 18 01 N | 083 28 25 W |