Atlantic Beach is a city in Duval County, Florida, United States. When the majority of communities in Duval County consolidated with Jacksonville, Florida in 1968, Atlantic Beach, along with Jacksonville Beach, Neptune Beach, and Baldwin, Florida, remained quasi-independent. Like the other towns, it maintains its own municipal government but its residents
vote in the Jacksonville mayoral election and have representation on the Jacksonville city council. The population was 13,368
at the 2000 census. According to the U.S Census estimates of 2005, the city had a population of 13,436. 
Atlantic Beach took off around 1900 after Henry Flagler built the Mayport stop of his East Coast Railway to the north of the town. The Atlantic Beach Corporation bought and developed most of the land in what is
now Atlantic Beach in 1915, and the town was incorporated in 1926.
is part of the Jacksonville Beaches community.
As of the censusGR2 of 2000, there were 13,368 people, 5,623 households, and 3,643 families residing in the city. The population density was 1,383.8/km² (3,584.3/mi²). There were 6,003 housing units at an average density of 621.4/km²
(1,609.5/mi²). The racial makeup of the city was 82.23% White, 12.69% African American, 0.26% Native American, 2.09% Asian, 0.03% Pacific Islander, 1.12% from other races, and 1.58% from two or more races. Hispanic or Latino of any race were 4.18% of the population.
There were 5,623 households out of which 28.2% had children under
the age of 18 living with them, 48.9% were married couples living together, 12.4% had a female householder with no husband present, and 35.2% were non-families. 26.5%
of all households were made up of individuals and 9.8% had someone living alone who was 65 years of age or older. The average
household size was 2.36 and the average family size was 2.86.
In the city the population was spread out with 22.5% under the age
of 18, 7.0% from 18 to 24, 30.9% from 25 to 44, 24.3% from 45 to 64, and 15.4% who were 65 years of age or older. The median
age was 39 years. For every 100 females there were 94.7 males. For every 100 females age 18 and over, there were 91.2 males.
The median income for a household
in the city was $48,353, and the median income for a family was $53,854. Males had a median income of $37,438 versus $27,321
for females. The per capita income for the city was $28,618. About 5.7% of families and 8.8% of the population were below the poverty line, including 14.3% of those under age 18 and 5.8% of those age 65 or over.