Duval County is in the northeastern part of the U.S. state of Florida. As of July 2022, the population was 1,016,536, up from 864,263 in 2010. It is Florida's sixth-most populous county. Its county seat is Jacksonville, with which the Duval County government has been consolidated since 1968. Duval County was established in 1822, and is named for William Pope Duval, Governor of Florida Territory from 1822 to 1834. Duval County is the central county of the Jacksonville Metropolitan Statistical Area.

Florida's First Coast, or simply the First Coast, is a region of the U.S. state of Florida, located on the Atlantic coast of North Florida. The First Coast refers to the same general area as the directional region of Northeast Florida. It consists roughly of the counties abutting Jacksonville—Duval, Baker, Clay, Nassau, and St. Johns—and nearby Flagler County and Putnam County. The name originated in a marketing campaign in the 1980s, and has become part of Florida's regional vernacular.