Northampton County is a county located in the U.S. state of Pennsylvania. It was formed in 1752 from parts of Bucks County with the county seat of Easton. Its namesake was Northamptonshire and the country house, Easton Neston. As of 2010, the population was 297,735.

Northampton County is located in Pennsylvania's Lehigh Valley. Its northern edge borders The Poconos. The eastern section of the county borders the Delaware River, which divides Pennsylvania and New Jersey. It is bordered on the west by Lehigh County, Pennsylvania, the Lehigh Valley's more highly populated county.

The county is industrially-oriented, producing anthracite coal, cement, and other industrial products. Bethlehem Steel, once one of the world's largest manufacturers of steel, was located there prior to its closing in 2003.