Calcutta is an unincorporated community and census-designated place in southeastern Columbiana County, Ohio, United States. The population was 3,941 at the 2020 census. Historically a rural town, Calcutta grew as businesses from neighboring East Liverpool moved into larger shopping centers clustered around Ohio State Route 170.

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.