York County is a county in the Commonwealth of Pennsylvania, United States. As of the 2020 census, the population was 456,438. Its county seat is York. The county was created on August 19, 1749, from part of Lancaster County and named either after the Duke of York, an early patron of the Penn family, or for the city and county of York in England. The county is part of the South Central region of the state.

York is a city in, and the county seat of, York County, Pennsylvania, United States. Located in South Central Pennsylvania, the city's population was 44,800 at the time of the 2020 census, making it the tenth-most populous city in Pennsylvania. The city has an urban area population of 238,549 people and a metropolitan population of 456,438 people.