Liberty Borough is located in Allegheny County, Pennsylvania. The population was 2,551 citizens according to the 2010 census.
Liberty Borough is part of the South Allegheny School District, along with Glassport, Lincoln, and Port Vue. Liberty is home to the district's high school.
Liberty Borough was at one time part of Port Vue but gained its "liberty" from Port Vue in 1912, thus the origin of the name of the town.
Liberty is bounded by Port Vue and McKeesport to the north, Versailles and the Youghiogheny River to the east, Lincoln to the south, and Glassport to the west.
Liberty Borough has a total area of 1.5 square miles, of which 1.4 square miles is land and 0.1 square miles is water.