Ludwig Andreas Olsen (1845 – February 20, 1886), also known as Louis Williams, was a United States Navy sailor and one of only 19 people to ever be awarded two Medals of Honor.

Both awards were for non-combat actions rescuing fellow seamen.

On 16 March 1883, aboard the screw sloop-of-war USS Lackawanna off Honolulu, Hawaii, Olsen jumped overboard and saved a fellow sailor from drowning.

The next year, on 13 June 1884 off the coast of Callao, Peru, Olsen again saved a man from drowning, along with Ordinary Seaman Isaac L. Fasseur.

Lackawanna, 16 March 1883, at Honolulu, Territory of Hawaii, and rescuing from drowning Thomas Moran, landsman.