Allen Township is a township in Northampton County, Pennsylvania, United States. The population of Allen Township was 4,269 at the 2010 census. Allen Township is part of the Lehigh Valley metropolitan area, which had a population of 861,899 and was the 68th-most populous metropolitan area in the U.S. as of the 2020 census.

Northampton County is a county in the Commonwealth of Pennsylvania, United States. As of the 2020 census, the population was 312,951. Its county seat is Easton. The county was formed in 1752 from parts of Bucks County. Its namesake was the county of Northamptonshire in England, and the county seat of Easton was named for Easton Neston, a country house in Northamptonshire. The county is part of the Southeast Pennsylvania region of the state.