9 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Warren | 1 | 38,442 | 39,164 | -0.31% | 2,409 | 16 | City |
| Niles | 2 | 18,147 | 18,419 | -0.25% | 2,110 | 9 | City |
| Girard | 3 | 9,394 | 9,574 | -0.32% | 1,665 | 6 | City |
| Hubbard | 4 | 7,538 | 7,619 | -0.17% | 1,871 | 4 | City |
| Cortland | 5 | 7,056 | 7,095 | -0.08% | 1,630 | 4 | City |
| Newton Falls | 6 | 4,520 | 4,567 | -0.18% | 1,530 | 3 | Village |
| West Farmington | 7 | 532 | 538 | -0.19% | 589 | 1 | Village |
| Orangeville | 8 | 168 | 174 | -0.59% | 226 | 1 | Village |
| Yankee Lake | 9 | 72 | 74 | 0% | 128 | 1 | Village |
Warren is the largest city in Trumbull County, with a population of 38,442.
Yankee Lake is the smallest city in Trumbull County, with a population of 72.
There are 9 cities in Trumbull County, Ohio.