Briar Creek is located in eastern Columbia County on the north side of the Susquehanna River.  It is bordered to the east by Berwick, to the north by Briar Creek Township, to the west by South Centre Township, and to the south, across the Susquehanna, by Mifflin Township.  Mifflinville is across the river southwest of Briar Creek, accessible by Market Street Bridge west of the borough limits.

According to the United States Census Bureau, the borough of Briar Creek has a total area of 1.9 square miles, of which 1.7 square miles is land and 0.2 square miles, or 10.38%, is water. Briar Creek is served by U.S. Route 11, which follows the Susquehanna River, leading east into Berwick and southwest 10 miles to Bloomsburg, the county seat. Although Briar Creek is one of the smaller boroughs in Pennsylvania, it is home to many acres of farmland, a golf course, and a lake. A creek with the same name as the borough flows through Briar Creek.