Carroll County is located in the U.S. state of Maryland. As of the 2020 census, the population was 172,891. Its county seat is Westminster.

Westminster is a city in and the county seat of Carroll County, Maryland, United States. The city's population was 19,960 at the 2020 census. Westminster is an outlying community in the Baltimore metropolitan area, which is part of the greater Washington–Baltimore combined statistical area.