Gaston County is a county in the U.S. state of North Carolina. As of the 2020 census, the population was 227,943. The county seat is Gastonia. Dallas served as the original county seat from 1846 until 1911. Gaston County is included in the Charlotte-Concord-Gastonia, NC-SC Metropolitan Statistical Area, which had an estimated population of 2,805,115 in 2023. The county is located in the southern Piedmont region.