Mahoning County is a county in the U.S. state of Ohio. As of the 2020 census, the population was 228,614. Its county seat and largest city is Youngstown. The county is named after the Mahoning River and was formed on March 1, 1846; the 83rd county in Ohio.

Youngstown is a city in and the county seat of Mahoning County, Ohio, United States. At the 2020 census, it had a population of 60,068, making it the 11th-most populous city in Ohio. It is a principal city of the Youngstown–Warren metropolitan area, which had 430,591 residents in 2020 and is the seventh-largest metro area in Ohio. Youngstown is situated on the Mahoning River in Northeast Ohio, 58 miles (93 km) southeast of Cleveland and 61 miles (100 km) northwest of Pittsburgh.