| Pittsburg, Illinois | |
| Settlement Type: | Unincorporated community |
| Pushpin Map: | USA Illinois |
| Pushpin Label: | Pittsburg |
| Pushpin Label Position: | top |
| Pushpin Map Caption: | Location within the state of Illinois |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Illinois |
| Subdivision Type2: | County |
| Subdivision Name2: | Fayette |
| Subdivision Type3: | Township |
| Subdivision Name3: | Seminary |
| Unit Pref: | Imperial |
| Population As Of: | 2000 |
| Population Density Km2: | auto |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 531 |
| Coordinates: | 38.8714°N -89.2117°W |
| Postal Code Type: | ZIP codes |
| Blank Name: | FIPS code |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 415747 |
Pittsburg (also Halbsville) is an unincorporated community in Fayette County, Illinois, United States. Located at 38.8714°N -89.2117°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.