Dupo, Illinois

Dupo
Location of Dupo in St. Clair County, Illinois.
Coordinates: 38°30′47″N 90°13′36″W / 38.51306°N 90.22667°W / 38.51306; -90.22667
CountryUnited States
StateIllinois
CountySt. Clair
Area
 • Total
6.42 sq mi (16.64 km2)
 • Land6.40 sq mi (16.58 km2)
 • Water0.023 sq mi (0.06 km2)
Elevation
410 ft (120 m)
Population
 (2020)
 • Total
3,996
 • Density624.1/sq mi (240.96/km2)
Time zoneUTC-6 (CST)
 • Summer (DST)UTC-5 (CDT)
ZIP code
62239
Area code618
FIPS code17-21254
GNIS ID2398759
Websitewww.villageofdupo.org

Dupo is a village in St. Clair County, Illinois, United States. As of the 2020 census, Dupo had a population of 3,996. The village was settled in about 1750 and was incorporated in 1907. Its modern name, adopted in the early 20th century, is shortened from Prairie du Pont ("Bridge Prairie").