Founded on Dec 31, 1821, Marion County is one of 92 counties in the state of Indiana. Historically, Marion County was formed from Delaware New Purchase. The city of Indianapolis is the county seat. With FIPS code of 97, Marion County has a population of 971,102 and area of 396 square miles (1,026 km2).
List of all cities in Marion County, IN alphabetically
| City/Town | Postal Code | Area Code |
| Acton, IN | 46259 | 317 |
| Army Finance Center, IN | 46249 | 317 |
| B M G, IN | 46291 | 317 |
| Beech Grove, IN | 46107 | 317 |
| Bridgeport, IN | 46231 | 317 |
| Brylane, IN | 46283 | 317 |
| Bus Rply, IN | 46209 | 317 |
| Business Reply, IN | 46209 | 317 |
| Castleton, IN | 46250 | 317 |
| 46256 | 317 | |
| Chase Bank, IN | 46266 | 317 |
| 46277 | 317 | |
| Clermont, IN | 46234 | 317 |
| Cumberland, IN | 46229 | 317 |
| Drexel Gardens, IN | 46241 | 317 |
| Eagle Creek, IN | 46214 | 317 |
| 46253 | 317 | |
| 46254 | 317 | |
| Eli Lilly Co, IN | 46285 | 317 |
| Fort Benjamin Harrison, IN | 46216 | 317 |
| Greater Indiana District, IN | 46298 | 317 |
| Huntington Bank, IN | 46262 | 317 |
| I U P U I, IN | 46223 | 317 |
| Indianapolis, IN | 46201 | 317 |
| 46202 | 317 | |
| 46203 | 317 | |
| 46204 | 317 | |
| 46205 | 317 | |
| 46206 | 317 | |
| 46207 | 317 | |
| 46208 | 317 | |
| 46209 | 317 | |
| 46211 | 317 | |
| 46214 | 317 | |
| 46216 | 317 | |
| 46217 | 317 | |
| 46218 | 317 | |
| 46219 | 317 | |
| 46220 | 317 | |
| 46221 | 317 | |
| 46222 | 317 | |
| 46223 | 317 | |
| 46224 | 317 | |
| 46225 | 317 | |
| 46226 | 317 | |
| 46227 | 317 | |
| 46228 | 317 | |
| 46229 | 317 | |
| 46230 | 317 | |
| 46231 | 317 | |
| 46234 | 317 | |
| 46235 | 317 | |
| 46236 | 317 | |
| 46237 | 317 | |
| 46239 | 317 | |
| 46240 | 317 | |
| 46241 | 317 | |
| 46242 | 317 | |
| 46244 | 317 | |
| 46247 | 317 | |
| 46249 | 317 | |
| 46250 | 317 | |
| 46251 | 317 | |
| 46253 | 317 | |
| 46254 | 317 | |
| 46255 | 317 | |
| 46256 | 317 | |
| 46259 | 317 | |
| 46260 | 317 | |
| 46262 | 317 | |
| 46266 | 317 | |
| 46268 | 317 | |
| 46274 | 317 | |
| 46275 | 317 | |
| 46277 | 317 | |
| 46278 | 317 | |
| 46282 | 317 | |
| 46283 | 317 | |
| 46285 | 317 | |
| 46291 | 317 | |
| 46295 | 317 | |
| 46296 | 317 | |
| 46298 | 317 | |
| Irvington, IN | 46219 | 317 |
| Lawrence, IN | 46226 | 317 |
| Mars Hill, IN | 46241 | 317 |
| Maywood, IN | 46241 | 317 |
| Merchants Bank, IN | 46255 | 317 |
| National City Bank, IN | 46255 | 317 |
| New Augusta, IN | 46268 | 317 |
| 46278 | 317 | |
| Nora, IN | 46240 | 317 |
| 46260 | 317 | |
| Oaklandon, IN | 46216 | 317 |
| 46235 | 317 | |
| 46236 | 317 | |
| Park Fletcher, IN | 46241 | 317 |
| Rca Mfg Co, IN | 46291 | 317 |
| Southport, IN | 46217 | 317 |
| 46227 | 317 | |
| 46237 | 317 | |
| 46247 | 317 | |
| Spdway, IN | 46224 | 317 |
| Spdwy, IN | 46224 | 317 |
| Speedway, IN | 46224 | 317 |
| Time Life Inc, IN | 46211 | 317 |
| 46275 | 317 | |
| Time/Life, IN | 46274 | 317 |
| Traders Point, IN | 46278 | 317 |
| Uptown, IN | 46205 | 317 |
| USPS Scanner REpair, IN | 46295 | 317 |
| USPS Symbol Repair, IN | 46296 | 317 |
| Wanamaker, IN | 46239 | 317 |
| West Indianapolis, IN | 46221 | 317 |
| West Newton, IN | 46183 | 317 |