Mons Monssen (January 20, 1867–February 10, 1930) was a sailor in the United States Navy who received the Medal of Honor for heroism while serving about the USS Missouri (BB-11).

Monssen was a chief gunners mate serving on USS Missouri (BB-11) on April 13, 1904, when a charge ignited while a 12-inch gun was being loaded for target practice.

Monssen entered the burning magazine through the scuttle and threw water on the fire with his hands until a hose was passed to him.

He died at the Naval Hospital, Brooklyn, New York, February 10, 1930 and is buried at Cypress Hills National Cemetery.

Missouri, for extraordinary heroism in entering a burning magazine through the scuttle and endeavoring to extinguish the fire by throwing water with his hands until a hose was passed to him, 13 April 1904.See USS Monssen for the two ships named in his honor.