Fort James Jackson (usually shortened to Fort Jackson and informally known as Old Fort Jackson) is a restored nineteenth-century fort located one mile east of Savannah, Georgia, on the Savannah River. It is currently operated by the Coastal Heritage Society as Old Fort Jackson, a National Historic Landmark.

The land on which the fort was built, was sold by Nichols Turnbull in 1808. Initially, a structure named Fort Mud was built, but was lost to fire in 1833.

Named in honor of James Jackson (1757–1806), a British-born political figure in Georgia, Fort Jackson was constructed between 1808 and 1812 to protect the city of Savannah from attack by sea. It was engineered by William McRee who had just graduated from West Point. During the American Civil War, it became one of three Confederate forts that defended Savannah from Union forces (the other two were Fort McAllister and Fort Pulaski).

When the Union army commanded by William T. Sherman captured Savannah by land in December 1864, it took Fort Jackson almost immediately.