Columbiana County is a county located in the U.S. state of Ohio. As of the 2020 census, the population was 101,877. The county seat is Lisbon and its largest city is Salem. Created in 1803, the county name is derived from that of 15th-century Italian explorer Christopher Columbus.

The region Northeast Ohio, in the US state of Ohio, in its most expansive usage contains six metropolitan statistical areas: Cleveland–Elyria, Akron, Canton–Massillon, Youngstown–Warren, Mansfield, and Weirton–Steubenville along with eight micropolitan statistical areas. Most of the region is considered either part of the Cleveland–Akron–Canton, OH Combined Statistical Area and media market or the Youngstown–Warren, OH–PA Combined Statistical Area and media market. In all, the region is home to: 4,502,460 residents. It is also a part of the Great Lakes megalopolis, containing over 54 million people. Northeast Ohio also includes most of the area known historically as the Connecticut Western Reserve.