Warren
- County:
- Trumbull County
- County Seat:
- Yes
- Area (mi²):
- 15.956
- State:
- Ohio
Warren is a city located in Trumbull County, Ohio. Warren has a 2026 population of 38,683. It is also the county seat of Trumbull County. Warren is currently declining at a rate of -0.18% annually and its population has decreased by -1.23% since the most recent census, which recorded a population of 39,164 in 2020.