Fort Jackson, Masonry fort in Plaquemines Parish, United States

Fort Jackson is a military fortification on the western bank of the Mississippi River in Plaquemines Parish, Louisiana, built from thick brick walls in the shape of a five-pointed star. The ramparts extend over several hectares and enclose a central parade ground, from which passageways lead to gun emplacements and underground storage rooms.

Construction of the fortification began in 1822 as part of a defense system to protect New Orleans and was completed in 1832 after US military engineers revised colonial-era plans. In April 1862, Union forces bombarded the installation during a multi-day battle that ended with Confederate surrender and opened the Mississippi River to northern forces.

The fort is named for Andrew Jackson, who advised its construction after the War of 1812. Since 1970 its grounds have hosted the Plaquemines Parish Fair and Orange Festival. The museum with the weapons, uniforms and documents is not at the fort: it occupies the parish's District 9 office at 38039 Hwy 23 in Buras, about 1 mile southwest.

Fort Jackson lies about 70 miles (110 km) south of New Orleans on the west bank of the Mississippi, roughly 2.5 miles south of Triumph. The fort grounds are open as a park, but the interior is only occasionally accessible. The Fort Jackson Museum is not at the fort site; it is about 1 mile southwest at 38039 Hwy 23, Buras, in the parish's District 9 office.

French champagne producer Charles Heidsieck spent seven months at the installation after Confederate soldiers arrested him on suspicion of espionage. His detention in 1862 ended only when French diplomats intervened and secured his release.