The Foless Security Force (FSF) was the planetary defense force of the planet Foless in the Colonies region. During the time of the Clone Wars, it had about five million personnel and maintained a sizable fleet of Dreadnought-class heavy cruisers, Carrack-class light cruisers, and other vessels. The FSF fought during the Battle of Foless, defending the planet alongside the central Republic Military from the Confederacy of Independent Systems.
The FSF remained active into the reign of the Galactic Empire, continuing to protect Foless despite efforts to supplant it by the Imperial Military. When Foless fell under control of the New Republic near the end of the Galactic Civil War, the Foless Security Force changed its loyalty to the new dominant government.