Volusia County (, vo-LOO-sha) is located in the east-central part of the U.S. state of Florida between the St. Johns River and the Atlantic Ocean. As of the 2020 census, the county was home to 553,543 people, an increase of 11.9% from the 2010 census. It was founded on December 29, 1854, from part of Orange County, and was named for the community of Volusia, located in northwestern Volusia County. Its first county seat was Enterprise. Since 1887, its county seat has been DeLand.

Volusia County is part of the Deltona-Daytona Beach-Ormond Beach metropolitan statistical area, as well as part of the larger Orlando-Deltona-Daytona Beach Combined statistical area.