Jacksonville is the most populous city in the state of Florida and the thirteenth most populous city in the United States. It is the county seat of Duval County. Since 1968, the city has shared a consolidated government with the county, making it the largest city in land area in the contiguous United States. In 2006, the city proper had an estimated population of 834,789 with a metropolitan population of more than 1.3 million. Jacksonville is the third most populated city on the East Coast, after New York City and Philadelphia. It is the central city of the Jacksonville Metropolitan Statistical Area.

As of the census estimates of 2005, there were 782,623 people, 284,499 households, and 190,614 families residing in the city. The population density was 374.9/km² (970.9/mi²). There were 308,826 housing units at an average density of 157.4/km² (407.6/mi²). The racial makeup of the city was 64.48% White, 34.03% Black or African American, 0.34% Native American, 2.78% Asian, 0.06% Pacific Islander, 1.33% from other races, and 1.99% from two or more races. 4.16% of the population were Hispanic or Latino of any race. Jacksonville has, as named by the census the 10th largest Arab population in the United States. There were 284,499 households out of which 33.9% had children under the age of 18 living with them, 46.7% were married couples living together, 16.0% had a female householder with no husband present, and 33.0% were non-families.