Founded in Jul 10, 1800, Trumbull County is one of 88 counties in the state of Ohio. Historically, Trumbull County was formed from Jefferson and Wayne Counties. The city of Warren is the county seat. With FIPS code of 155, Trumbull County has a population of 201,335 and area of 616.48 square miles (1,597 km2).
List of all cities in Trumbull County, OH alphabetically
| City/Town | Postal Code | Area Code |
| Bazetta, OH | 44410 | 330/234 |
| Braceville, OH | 44444 | 330/234 |
| Bristolville, OH | 44402 | 330/234 |
| Brookfield, OH | 44403 | 330/234 |
| Burghill, OH | 44404 | 330/234 |
| Business Reply, OH | 44488 | 330/234 |
| Champion, OH | 44483 | 330/234 |
| Cortland, OH | 44410 | 330/234 |
| Farmdale, OH | 44417 | 330/234 |
| Fowler, OH | 44418 | 330/234 |
| Girard, OH | 44420 | 330/234 |
| Greene, OH | 44450 | 440 |
| Gustavus, OH | 44417 | 330/234 |
| Hartford, OH | 44424 | 330/234 |
| Howland, OH | 44484 | 330/234 |
| Hubbard, OH | 44425 | 330/234 |
| Kinsman, OH | 44428 | 330/234 |
| Leavittsburg, OH | 44430 | 330/234 |
| Lockwood, OH | 44450 | 440 |
| Lordstown, OH | 44481 | 330/234 |
| Masury, OH | 44438 | 330/234 |
| Mayburn Corners, OH | 44417 | 330/234 |
| Mc Donald, OH | 44437 | 330/234 |
| Mecca, OH | 44410 | 330/234 |
| Mesopotamia, OH | 44439 | 440 |
| Mineral Ridge, OH | 44440 | 330/234 |
| Newton Falls, OH | 44444 | 330/234 |
| Niles, OH | 44446 | 330/234 |
| North Bloomfield, OH | 44450 | 440 |
| Oakfield, OH | 44450 | 440 |
| Orangeville, OH | 44453 | 330/234 |
| Packard Elec Co Div Gm, OH | 44486 | 330/234 |
| Southington, OH | 44470 | 330/234 |
| Vernon, OH | 44428 | 330/234 |
| 44473 | 330/234 | |
| 44481 | 330/234 | |
| 44482 | 330/234 | |
| 44483 | 330/234 | |
| 44484 | 330/234 | |
| 44485 | 330/234 | |
| 44486 | 330/234 | |
| 44488 | 330/234 | |
| West Farmington, OH | 44491 | 330/234 |
| West Mecca, OH | 44410 | 330/234 |
| Yankee Lake, OH | 44403 | 330/234 |