Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Delaware County | Civil | 290 | Delaware | 40 16 00 N | 083 00 01 W |
| Delaware County Courthouse | Building | 274 | Delaware | 40 18 07 N | 083 04 05 W |
| Delaware County Cultural Arts Center | Building | 272 | Delaware | 40 18 01 N | 083 04 33 W |
| Delaware County Fairgrounds | Locale | 280 | Delaware | 40 19 00 N | 083 04 30 W |
| Delaware County Home | Building | 290 | Delaware | 40 19 56 N | 082 58 29 W |
| Delaware County Jail | Building | 284 | Delaware | 40 18 44 N | 083 02 53 W |
| Delaware County Law Library | Building | 274 | Delaware | 40 18 07 N | 083 04 05 W |
| Delaware County Library | Building | 263 | Delaware | 40 17 59 N | 083 03 52 W |
| Delaware Creek | Stream | | Lucas | 41 36 35 N | 083 35 26 W |
| Delaware Dam | Dam | 275 | Delaware | 40 21 31 N | 083 04 09 W |
| Delaware Hall | Building | 240 | Franklin | 39 58 13 N | 082 59 18 W |
| Delaware Industrial Park | Locale | 288 | Delaware | 40 17 06 N | 083 06 08 W |
| Delaware Island | Island | 175 | Lucas | 41 36 29 N | 083 35 15 W |
| Delaware Joint Vocational School | School | 287 | Delaware | 40 17 52 N | 083 01 44 W |
| Delaware Lake | Reservoir | 274 | Delaware | 40 21 31 N | 083 04 09 W |
| Delaware Meadows (subdivision) | Populated Place | 287 | Delaware | 40 17 48 N | 083 05 28 W |
| Delaware Municipal Airport | Airport | 287 | Delaware | 40 16 45 N | 083 06 21 W |
| Delaware Post Office | Post Office | 265 | Delaware | 40 17 49 N | 083 04 06 W |
| Delaware Post Office | Post Office | 265 | Delaware | 40 17 55 N | 083 04 05 W |
| Delaware Reservoir Landing Strip | Airport | 287 | Delaware | 40 22 27 N | 083 04 01 W |
| Delaware Reservoir Wildlife Area | Park | 282 | Delaware | 40 24 29 N | 083 02 41 W |
| Delaware Run | Stream | | Delaware | 40 17 53 N | 083 03 45 W |
| Delaware Seventh Day Adventist Church | Church | 272 | Delaware | 40 18 07 N | 083 04 02 W |
| Delaware Shopping Center | Locale | 272 | Delaware | 40 17 35 N | 083 04 01 W |
| Delaware Square Shopping Center | Locale | 275 | Delaware | 40 16 25 N | 083 04 13 W |
| Delbert Shetler Farm Cemetery | Cemetery | 353 | Holmes | 40 31 08 N | 081 44 51 W |
| Delco Plaza of Delhi Shopping Center | Locale | 262 | Hamilton | 39 05 40 N | 084 36 45 W |
| Delco Plaza Shopping Center | Locale | 245 | Clermont | 39 11 30 N | 084 15 27 W |
| Delco Plaza Shopping Center | Locale | 262 | Hamilton | 39 13 52 N | 084 35 16 W |
| Delco Plaza Shopping Center | Locale | 298 | Marion | 40 33 55 N | 083 07 24 W |
| Delhi | Populated Place | 274 | Hamilton | 39 05 42 N | 084 36 19 W |
| Delhi Christian Church | Church | 169 | Hamilton | 39 05 38 N | 084 34 24 W |
| Delhi Church of Christ | Church | 155 | Hamilton | 39 06 21 N | 084 41 10 W |
| Delhi Hills | Populated Place | 266 | Hamilton | 39 05 34 N | 084 36 46 W |
| Delhi Hills Baptist Church | Church | 267 | Hamilton | 39 06 30 N | 084 37 27 W |
| Delhi Hills Golf Course | Locale | 255 | Hamilton | 39 07 00 N | 084 38 59 W |
| Delhi Junior High School | School | 275 | Hamilton | 39 06 17 N | 084 36 59 W |
| Delhi Plaza Shopping Center | Locale | 223 | Hamilton | 39 05 45 N | 084 35 23 W |
| Delhi Post Office (historical) | Post Office | 275 | Hamilton | 39 05 40 N | 084 36 20 W |
| Delhi School (historical) | School | 280 | Brown | 38 55 55 N | 083 54 02 W |
| Delhi Shopping Center | Locale | 239 | Hamilton | 39 06 41 N | 084 38 02 W |
| Delhi Township Park | Park | 260 | Hamilton | 39 06 01 N | 084 35 44 W |
| Delhurst Lake | Reservoir | 248 | Hamilton | 39 07 13 N | 084 39 11 W |
| Delightful | Populated Place | 288 | Trumbull | 41 17 10 N | 080 55 30 W |
| Delightful Cemetery | Cemetery | 287 | Trumbull | 41 17 04 N | 080 55 17 W |
| Delightful Evangelical Congregational Church | Church | 286 | Trumbull | 41 17 07 N | 080 55 32 W |
| Delightful Post Office (historical) | Post Office | 288 | Trumbull | 41 17 10 N | 080 55 29 W |
| Deline Ditch | Canal | 186 | Lucas | 41 38 48 N | 083 39 33 W |
| Delisle | Populated Place | 321 | Darke | 40 01 10 N | 084 34 27 W |
| Delisle Post Office (historical) | Post Office | 320 | Darke | 40 01 10 N | 084 34 25 W |
| Deliverance Center Church of God in Christ | Church | 256 | Franklin | 39 59 43 N | 082 58 47 W |
| Deliverance Church of God | Church | 236 | Franklin | 39 59 08 N | 082 56 48 W |
| Deliverance Tabernacle | Church | 183 | Butler | 39 23 12 N | 084 32 59 W |
| Deliverance Tabernacle | Church | 300 | Summit | 41 05 01 N | 081 34 36 W |
| Deliverance Temple | Church | 164 | Hamilton | 39 06 50 N | 084 31 09 W |
| Deliverance Temple Church | Church | 231 | Hamilton | 39 07 15 N | 084 30 14 W |
| Deliverance Temple Church of Christ | Church | 300 | Marion | 40 36 15 N | 083 07 41 W |
| Dell | Populated Place | 187 | Washington | 39 24 45 N | 081 21 23 W |
| Dellroy | Populated Place | 292 | Carroll | 40 33 16 N | 081 11 58 W |
| Dellroy Creek | Stream | | Carroll | 40 33 25 N | 081 12 03 W |
| Dellroy Elementary School | School | 287 | Carroll | 40 33 17 N | 081 11 43 W |
| Dellroy Post Office | Post Office | 293 | Carroll | 40 33 15 N | 081 11 59 W |
| Dellwood Park | Park | 299 | Cuyahoga | 41 21 48 N | 081 32 09 W |
| Delmont | Populated Place | 318 | Fairfield | 39 40 58 N | 082 40 51 W |
| Delmont Post Office (historical) | Post Office | 314 | Fairfield | 39 41 00 N | 082 40 50 W |
| DeLong Cemetery | Cemetery | 194 | Washington | 39 35 00 N | 081 40 31 W |
| DeLoss Creek | Stream | | Lawrence | 38 35 38 N | 082 29 44 W |
| Delphi | Populated Place | 317 | Huron | 41 01 52 N | 082 36 28 W |
| Delphi Cemetery | Cemetery | 314 | Huron | 41 01 51 N | 082 36 44 W |
| Delphos | Populated Place | 236 | Allen | 40 50 36 N | 084 20 30 W |
| Delphos Airport | Airport | 239 | Allen | 40 49 15 N | 084 18 45 W |
| Delphos City Park | Park | 236 | Van Wert | 40 50 36 N | 084 20 33 W |
| Delphos Country Club | Locale | 228 | Putnam | 40 54 20 N | 084 22 01 W |
| Delphos Post Office | Post Office | 237 | Allen | 40 50 37 N | 084 20 24 W |
| Delphos Water Works | Locale | 235 | Allen | 40 50 07 N | 084 20 16 W |
| Delphos Wesleyan Church | Church | 236 | Van Wert | 40 50 03 N | 084 21 05 W |
| Delray Church of Christ in Christian Union | Church | 223 | Franklin | 39 54 40 N | 082 59 20 W |
| Delshire Elementary School | School | 263 | Hamilton | 39 05 23 N | 084 35 49 W |
| Delshire Park | Park | 257 | Hamilton | 39 05 17 N | 084 35 31 W |
| Delta | Populated Place | 220 | Fulton | 41 34 25 N | 084 00 19 W |
| Delta Assembly of God Church | Church | 222 | Fulton | 41 34 32 N | 084 00 35 W |
| Delta Church of the Nazarene | Church | 224 | Fulton | 41 34 27 N | 084 01 21 W |
| Delta Elementary School | School | 220 | Fulton | 41 34 42 N | 084 00 06 W |
| Delta Heights (subdivision) | Populated Place | 225 | Fulton | 41 34 50 N | 084 00 37 W |
| Delta Industrial Park | Locale | 219 | Fulton | 41 34 24 N | 083 59 25 W |
| Delta Land and Investment Company Reservoir | Reservoir | 312 | Medina | 41 06 24 N | 081 49 05 W |
| Delta Land and Investment Company Reservoir | Reservoir | 311 | Medina | 41 06 36 N | 081 49 11 W |
| Delta Memorial Hall | Building | 220 | Fulton | 41 34 27 N | 084 00 19 W |
| Delta Methodist Church (historical) | Church | 221 | Fulton | 41 34 30 N | 084 00 35 W |
| Delta Middle School | School | 220 | Fulton | 41 34 41 N | 084 00 08 W |
| Delta Municipal Park | Park | 221 | Fulton | 41 34 49 N | 084 00 05 W |
| Delta Post Office | Post Office | 220 | Fulton | 41 34 27 N | 084 00 28 W |
| Delta Public Library | Building | 220 | Fulton | 41 34 26 N | 084 00 21 W |
| Delta Reservoir | Reservoir | 223 | Fulton | 41 35 24 N | 084 00 42 W |
| Delta Reservoir Dam | Dam | 223 | Fulton | 41 35 24 N | 084 00 42 W |
| Delta Wings Airport | Airport | 217 | Fulton | 41 34 20 N | 083 59 05 W |
| Delta-Columbia United Methodist Church | Church | 156 | Hamilton | 39 06 38 N | 084 26 04 W |
| Deluxe Mobile Home Park (subdivision) | Populated Place | 186 | Wood | 41 35 54 N | 083 29 18 W |
| Delvin (historical) | Populated Place | 302 | Darke | 40 19 30 N | 084 32 04 W |
| Delvin Post Office (historical) | Post Office | 302 | Darke | 40 19 30 N | 084 32 05 W |
| Delwood Childrens Home | Building | 274 | Delaware | 40 18 52 N | 083 04 04 W |
| Delwood Run | Stream | | Medina | 41 14 18 N | 081 55 28 W |
| Demazie Hollow | Valley | | Adams | 38 41 32 N | 083 18 43 W |
| Deming Cemetery | Cemetery | 230 | Washington | 39 29 18 N | 081 34 56 W |
| Deming Residence Hall | Building | 238 | Hancock | 41 03 09 N | 083 39 10 W |
| Demings Arbor Lake | Lake | 297 | Medina | 41 06 53 N | 081 48 58 W |
| Demmitt Elementary School | School | 291 | Montgomery | 39 53 31 N | 084 10 37 W |
| Demorest Road Shopping Center | Locale | 252 | Franklin | 39 55 46 N | 083 05 22 W |
| Dempsey Hall | Building | 321 | Knox | 40 22 25 N | 082 23 44 W |
| Dempsey Playground | Park | 251 | Hamilton | 39 06 29 N | 084 33 46 W |