Pennsylvania's major cities include Philadelphia, Pittsburgh, Allentown, Erie, and Scranton. Philadelphia, the largest city, serves as the state's economic and cultural hub with a population exceeding 1.5 million. Pittsburgh, known for its industrial transformation, ranks second in population and hosts leading healthcare and technology sectors. Allentown, Erie, and Scranton follow, each contributing to regional manufacturing, education, and tourism.

The prominence of these cities stems from Pennsylvania's historical economic diversity and strategic geographic positioning. Philadelphia's dominance is reinforced by its port, healthcare institutions, and educational institutions like the University of Pennsylvania, which drive innovation and employment. Pittsburgh's shift from steel to advanced manufacturing and tech has made it a national model for economic revitalization, supported by a skilled workforce and partnerships with universities like Carnegie Mellon. Allentown benefits from proximity to Philadelphia and a growing healthcare sector, while Erie's economy relies on manufacturing and tourism, anchored by Presque Isle State Park. Scranton's economy is bolstered by healthcare (e.g., Geisinger Health System) and higher education, with a population of nearly 100,000.

Data from the U.S. Census Bureau (2020) confirms Philadelphia's population of 1,536,504, making it the largest city in Pennsylvania. Pittsburgh's population of 310,630 positions it as a critical industrial and tech center. Allentown (120,633) and Erie (100,392) are regional economic anchors, while Scranton (95,861) remains vital for healthcare and education. Pennsylvania's state government reports highlight manufacturing and healthcare as key industries, with cities like Pittsburgh and Allentown contributing over 20% of the state's total manufacturing output. These cities' adaptability to economic shifts and infrastructure investments ensure their sustained importance in Pennsylvania's urban landscape.