Trumbull County, Ohio, USA
County or equivalent
Location overview
Trumbull County lies in northeastern Ohio near the Pennsylvania border, with Warren as its county seat and Niles, Girard and Hubbard among its other communities. A gently rolling landscape of glaciated plains, woodlands and streams surrounds the Mahoning River and Mosquito Creek Lake. The county was established in 1800 within the Connecticut Western Reserve and once covered a much larger portion of northeastern Ohio. Trumbull County had about 199,000 residents in 2025. Manufacturing remains an important part of the local economy, joined by health care, logistics, retail, agriculture and new investment in advanced energy and technology.