Brownstown is a village in Fayette County, Illinois, United States.

[4] U.S. Route 40 passes through the south side of the village, leading east 6 miles (10 km) to St. Elmo and west 8 miles (13 km) to Vandalia, the Fayette County seat.

Interstate 70 passes just south of Brownstown, with the closest exit 3 miles (5 km) west at US 40.

According to the 2021 census gazetteer files, Brownstown has a total area of 0.76 square miles (1.97 km2), all land.

Brownstown is host to the annual Fayette County Fair, held each summer in mid-July.