[4] Brownstown is in central Lancaster County, in the western section of West Earl Township.

The main route through Brownstown is Pennsylvania Route 772 (South State Street), which leads northwest 6 miles (10 km) to Lititz and southeast 3 miles (5 km) to Leola.

U.S. Route 222, a four-lane expressway, runs just to the west of the center of town, with access via an interchange with PA 772.

The intersection of routes 772 and 272 is currently one of the most heavily traveled areas in Lancaster County.

[5] The Conestoga River forms the southern boundary of the community, and Cocalico Creek forms the western boundary (and of West Earl Township), joining the Conestoga southwest of the center of town.