acksonville is the most populous city proper in the U.S. state of Florida, located on the Atlantic coast of northeastern Florida. It is the seat of Duval County,[9] with which the City of Jacksonville consolidated in 1968.As of July 2022, Jacksonville's population was 971,319, while the population of Duval County was about 1 million. After consolidation, Jacksonville became the most populous city in Florida and the Southeastern United States, and the largest in the South outside the state of Texas. With a population of 1,733,937, the Jacksonville metropolitan area ranks as Florida's fourth-largest metropolitan region.[7] The metropolitan area consists of Clay County, St. Johns County, Nassau County, and Baker County.