Elizabeth is a borough in Allegheny County, Pennsylvania on the east bank of the Monongahela river, where Pennsylvania Route 51 crosses, 15 miles upstream [south] of Pittsburgh and close to the county line. The population was 1,609 at the 2000 census. The borough of Elizabeth is entirely contained within the 15037 USPS ZIP code.
Elizabeth is located at 40°16′16″N 79°53′11″W / 40.27111°N 79.88639°W / 40.27111; -79.88639 (40.271189, -79.886347).
According to the United States Census Bureau, the borough has a total area of 0.4 square miles (1.1 km²), of which, 0.3 square miles (0.9 km²) of it is land and 0.1 square miles (0.2 km²) of it (14.63%) is water.