| Frank Du Moulin | |
| Birth Date: | c. 1850 |
| Birth Place: | Philadelphia, Pennsylvania |
| Placeofburial Label: | Place of burial |
| Allegiance: | United States |
| Branch: | United States Navy |
| Rank: | Apprentice |
| Awards: | Medal of Honor |
Frank Du Moulin (born c. 1850, date of death unknown) was a United States Navy sailor and a recipient of the United States military's highest decoration, the Medal of Honor.
Born in about 1850 in Philadelphia, Pennsylvania, Du Moulin joined the Navy from that state. By September 5, 1867, he was serving as an apprentice on the training ship in the harbor of New London, Connecticut. On that day, a crewmate, Apprentice D'Orsay, fell from the rigging of the Sabines mizzen-topmast into the water, striking the lower rigging and a boat davit on his way down. Du Moulin jumped overboard and rescued D'Orsay from drowning. For this action, he received the Medal of Honor the next month.
Du Moulin's official Medal of Honor citation reads:
On the 5th of September 1867, Du Moulin jumped overboard and saved from drowning Apprentice D'Orsay, who had fallen from the mizzen topmast rigging of the Sabine, in New London Harbor, and was rendered helpless by striking the mizzen rigging and boat davit in the fall.