The SS Spartan is a railroad car ferry on Lake Michigan owned by the Chesapeake and Ohio Railway (C&O) from 1952 through 1979. It alternated routes from Ludington, Michigan, to Milwaukee, Kewaunee, and Manitowoc, Wisconsin.

The SS Spartan today sits at Ludington's 21⁄2 slip, one of the last of the true railroad-car ferries remaining. Due to the rarity of her coal-burning Skinner Unaflow steam engines that she and the Badger share, the Spartan has been used frequently as a parts ship to keep her twin running. In the early 2000s, when a new passenger ferry service was proposed from Muskegon, Michigan to Milwaukee, Wisconsin, Lake Michigan Carferry (the owners of the Badger and Spartan since 1992) proposed a diesel-converted Spartan as the ship of choice for the run.