Flag of Philadelphia, Pennsylvania, on Retro TVs.
Philadelphia (colloquially known simply as Philly) is a city in the Commonwealth of Pennsylvania in the United States. It is the sixth-most-populous city in the United States and the most populous city in the state of Pennsylvania, with a 2020 population of 1,603,797. It is also the second-most populous city in the Northeastern United States, behind New York City. Since 1854, the city has had the same geographic boundaries as Philadelphia County, the most-populous county in Pennsylvania and the urban core of the eighth-largest U.S. metropolitan statistical area, with over 6 million residents as of 2017. Philadelphia is also the economic and cultural center of the greater Delaware Valley along the lower Delaware and Schuylkill rivers within