Carroll County is a county in the U.S. state of Mississippi. As of the 2020 census, the population was 9,998. Its county seats are Carrollton and Vaiden. The county is named for Charles Carroll of Carrollton, the last surviving signatory of the Declaration of Independence.

A county seat is an administrative center, seat of government, or capital city of a county or civil parish. The term is in use in five countries: Canada, China, Hungary, Romania, and the United States. An equivalent term, shire town, is used in the U.S. state of Vermont and in several other English-speaking jurisdictions. County towns usually serve a similar function in Ireland, Jamaica, and the United Kingdom.