Reading is a city in and the county seat of Berks County, Pennsylvania, United States. The city had a population of 95,112 at the 2020 censu…Reading is a city in and the county seat of Berks County, Pennsylvania, United States. The city had a population of 95,112 at the 2020 census and is the fourth-most populous city in Pennsylvania after Philadelphia, Pittsburgh, and Allentown. Reading is located in the southeastern part of the state and is the principal city of the Greater Reading area, which had 420,152 residents in 2020.