Lyndon is a Fourth Class city in Jefferson County and was incorporated on May 10, 1965.
At the main intersection in Lyndon is a historical marker placed by the Kentucky Historical Society and the Kentucky Department of Highways that says: "An early settler, Alvin Wood, named this community in 1871. One of America's oldest military institute founded in 1845; moved here in 1896.Points of interest in area: Central State Hospital, founded on site of Isaac Hite's home, and Oxmoor Farm, home of Alexander Scott Bullitt who helped draft first Kentucky State Constitution." The military institution that moved in 1896 was Kentucky Military Institute.