For the village in Williamson County, Illinois, see Pittsburg, Illinois
. For other uses, see Pittsburg (disambiguation).
Pittsburg (also Halbsville) is an unincorporated community in Fayette County, Illinois, United States. Located at 38°52′17″N 89°12′42″W / 38.87139°N 89.21167°W (38.8714354, -89.2117374), it lies at an elevation of 531 feet (162 m). It was named after the industrial heritage of Pittsburgh, Pennsylvania which, coincidentally, has a Fayette County, Pennsylvania as part of its metropolitan area.