Lincoln is a borough in Allegheny County, Pennsylvania, United States. The population was 1,072 at the 2010 census.As of 2009, the mayor is Nick Vay.Lincoln does not have its own post office. Three ZIP codes are used in the borough: 15133 for the northern portion of the borough adjacent to Liberty and 15135 for the eastern portion, with mail addressed to the city of McKeesport, and 15037 for the remainder of the borough, with mail addressed to Elizabeth.Lincoln is part of the South Allegheny School District, along with Liberty, Glassport and Port Vue.GeographyLincoln is located at . It is bounded by Glassport to the northwest, Liberty to the north, Versailles to the northeast, Elizabeth Township and the Youghiogheny River to the east and south, and Jefferson Hills, Clairton, and the Monongahela River to the west.