Nassau County, Florida

Nassau County, Florida
County
Nassau County Courthouse
Location within the U.S. state of Florida
Coordinates: 30°37′N 81°46′W / 30.61°N 81.77°W / 30.61; -81.77
Country United States
State Florida
FoundedDecember 29, 1824
Named afterDuchy of Nassau
SeatFernandina Beach
Largest communityYulee
Area
 • Total
726 sq mi (1,880 km2)
 • Land649 sq mi (1,680 km2)
 • Water77 sq mi (200 km2)  10.6%
Population
 (2020)
 • Total
90,352
 • Estimate 
(2023)
101,501
 • Density139/sq mi (53.8/km2)
Time zoneUTC−5 (Eastern)
 • Summer (DST)UTC−4 (EDT)
Congressional district4th
Websitewww.nassaucountyfl.com

Nassau County is located in the U.S. state of Florida. It is the northeasternmost county in the state. The county seat is Fernandina Beach. The population was 90,352 at the 2020 census.

Nassau County is a constituent of the Jacksonville, Florida Metropolitan Statistical Area, which accommodates around 1.68 million inhabitants as of 2022. The county is situated in Northeast Florida with a land area of 726 square miles (1,880 km2). Population growth in the county has increased by over 28,000 residents since the year 2000 as a result of Nassau's proximity to downtown Jacksonville, new housing developments, agricultural production, tourism locations, and a diversifying tax base with new industrial and commercial companies moving to the county. Nassau County is also a favored residential destination for military personnel stationed at bases in the adjacent Duval County, Florida (Naval Air Station Jacksonville, Naval Station Mayport) and Camden County, Georgia (Naval Submarine Base Kings Bay). Nassau County celebrated 200 years with its bicentennial celebration in 2024.