, giving the city a population density of 2,827/mi² (1,094/km²).Although the French Huguenots led by Captain Jean Ribault laid claim to the First Coast in 1562, it was the Spanish who first settled the Jacksonville Beach area, establishing missions from Mayport to St. Augustine. The Spanish ceded East Florida to the English by treaty in 1763 only to regain control twenty years later. In 1821 the Spanish ceded Florida to the United States of America. The Jacksonville Beaches area has been inhabited since at least 1837 when Mayport was made a port, but it was not until 1883 that the Jacksonville and Atlantic Railroad established "Ruby Beach" in modern-day Jacksonville Beach. The settlement was renamed "Pablo Beach" three years later, and was incorporated as a town in 1907. The name was changed to "Jacksonville Beach" in 1925.
Jacksonville Beach is the largest town in the Jacksonville Beaches community. It is the eastern terminus of U.S. Route 90, which ends at an intersections with State Road A1A three blocks from the Atlantic Ocean.
Jacksonville Beach is located at (30.284091, -81.396074).
According to the United States Census Bureau, the city has a total area of 56.9 km² (22.0 mi²). 19.9 km² (7.7 mi²) of it is land and 37.0 km² (14.3 mi²) of it (65.03%) is water.
Jacksonville Beach has a humid subtropical climate.
In the city the population was spread out with 18.0% under the age of 18, 8.7% from 18 to 24, 35.6% from 25 to 44, 24.7% from 45 to 64, and 13.0% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 100.7 males. For every 100 females age 18 and over, there were 99.7 males.
The median income for a household in the city was $46,922, and the median income for a family was $58,388. Males had a median income of $36,385 versus $30,055 for females. The per capita income for the city was $27,467. About 4.2% of families and 7.2% of the population were below the poverty line, including 8.2% of those under age 18 and 7.0% of those age 65 or over.
Jacksonville Beach is a separate municipality within the consolidated city of Jacksonville. As such, it has its own city manager, city council, and mayor, while but is subject to county-level governance by Jacksonville. In 2004, Fland Sharp was elected to a four year term as mayor.