Fort Pickens is a pentagonal shaped military fort on Santa Rosa Island in the Pensacola, Florida area. Named after American Revolutionary War hero Andrew Pickens, the fort was completed in 1834 and was one of the few forts in the Confederate South that remained in Union hands throughout the American Civil War.

The fort was used from 1834 until 1947.

Numerous captives from Indian Wars in the West were transported to the East Coast to be held as prisoners. From October 1886 to May 1887, Geronimo, a noted Apache war chief, was imprisoned in Fort Pickens along with several of his warriors. Their families were held at Fort Marion in St. Augustine.

Fort Pickens, part of the Third System of Fortifications, was one of only four forts in the South that remained in Union control throughout the Civil War.

The Confederates attacked the Fort on 09 October 1861 with a force of a thousand men, in what is now called the Battle of Santa Rosa Island. The attack came from the east, after forces landed four miles away. The attack was repelled by artillery and gunfire, and the Confederates retreated with about 90 casualties.

This fort was built using brick and mortar.