Catasauqua, referred to colloquially as Catty, is a borough in Lehigh County, Pennsylvania, settled in 1805 and chartered as a borough in 1853. Catasauqua is a suburb of Allentown, Pennsylvania in the Lehigh Valley region of the state. Catasauqua is included in the Allentown-Bethlehem-Easton, PA-NJ Metropolitan Statistical Area, which is also included in the New York City-Newark, New Jersey, NY-NJ-CT-PA Combined Statistical Area.
Historically, manufacturing was Catasauqua's principal industry, and, in 1839, it was the location of the first manufactured anthracite iron in the nation. Catasauqua's population in 1910 was 5,250. The population was 6,436 at the 2010 census.
Catasauqua is located at 40°39′11″N 75°28′3″W (40.652995, -75.467627). Nearby large communities include Allentown three miles (5 km) to the south and Bethlehem seven miles (11 km) to the east.
According to the United States Census Bureau, the borough has a total area of 1.3 square miles (3.4 km2), of which, 1.3 square miles (3.4 km2) of it is land and 0.04 square miles (0.10 km2 or 2.31%) of it is water. The Catasauqua Creek flows through the town.