Catasauqua 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 6,588 at the 2000 census. The word Catasauqua is shortened to "Catty" in local dialect when speaking of the place.