Centralia is a borough and near-ghost town in Columbia County, Pennsylvania, United States, part of Northeastern Pennsylvania. Its population declined from 1,000 in 1980 to five residents in 2020 because of a coal mine fire burning beneath the borough since 1962. Centralia, part of the Bloomsburg–Berwick metropolitan area, is the least-populated municipality in Pennsylvania. It is completely surrounded by Conyngham Township.