Bethlehem is a city located in Northampton and Lehigh counties in the Lehigh Valley region of eastern Pennsylvania. As of the 2020 census, it had a population of 75,781 residents, making it the second-largest city in the Lehigh Valley after Allentown and the seventh-largest city in Pennsylvania overall. The city's population is split between the two counties, with 55,639 residents in Northampton County and 19,343 in Lehigh County.
The city is situated along the Lehigh River, a 109-mile-long tributary of the Delaware River that has historically been central to the region's geography and development.