Yazoo County is a county located in the U.S. state of Mississippi. As of the 2020 census, the population was 26,743. The county seat is Yazoo City. It is named for the Yazoo River, which forms its western border. Its name is said to come from a Choctaw language word meaning "River of Death".

Yazoo City is the county seat of Yazoo County, Mississippi, United States. It was named after the Yazoo River, which, in turn was named by the French explorer Robert La Salle in 1682 as "Rivière des Yazous" in reference to the Yazoo tribe living near the river's mouth. Yazoo City is the principal city of the Yazoo City Micropolitan Statistical Area, which is part of the larger Jackson–Yazoo City Combined Statistical Area. According to the 2010 census, the population was 11,403. The most important industry in 2021 is a group of federal prisons.