USS Duluth (LPD-6), an Austin-class amphibious transport dock, is the second ship of the United States Navy named for the city in Minnesota.

The Austin class was a class of twelve amphibious transport dock ships in service with the United States Navy from 1965 to 2017. Note that the U.S. Naval Vessel Registry list separate Cleveland and Trenton class ships, but most sources lists them as a single class. Trenton was sold to India and is the only ship still active.