Fort Knox is a United States Army (United States Army) post in Kentucky south of Louisville (Louisville, Kentucky) and north of Elizabethtown (Elizabethtown, Kentucky). The convert109000acrehaadj=on base covers parts of Bullitt (Bullitt County, Kentucky), Hardin (Hardin County, Kentucky), and Meade (Meade County, Kentucky) counties. It currently holds the U.S. Army Armor Center, the U.S. Army Armor School (United States Army Armor School), and is used by both the Army and the Marine Corps (United States Marine Corps) to train crews on the M1 Abrams main battle tank (Tank classification#Main battle tank). The base is also one of five current locations for U.S. Army Basic Combat Training. The history of the US Armys Cavalry and Armored forces (Cavalry (United States)), and of General George S. Pattons career, can be found at the General George Patton Museum on the grounds of Fort Knox. Parts of the base in Hardin and Meade Counties form a census-designated place (CDP), which had a population of 12,377 at the 2000 census (United States Census, 2000).

The term "Fort Knox" is often used in American English as an analogue (Analogue (literature)) that conveys cutting-edge security, impregnability, and excessive wealth.