The Commandant's Quarters at the Dearborn Arsenal is a United States military structure located at 21950 Michigan Avenue in Dearborn, Michigan. Built in 1834, it is the oldest building in Dearborn still located on its original site. It is considered to be one of the seven most significant buildings in Michigan. It was designated as a Michigan State Historic Site in 1956 and listed on the National Register of Historic Places in 1970.