Supercargo is a term in maritime law (adapted from the Spanish sobrecargo, one over or in charge of a cargo) that refers to a person employed on board a vessel by the owner of cargo carried on the ship. The duties of a supercargo include managing the cargo owner's trade, selling the merchandise at the ports to which the vessel is sailing, and buying and receiving goods to be carried on the return voyage.
He or she has control of the cargo unless limited by his contract or other agreement. For instance, the supercargo has no authority over the stevedores and he has no role in the necessary preparatory work prior to the handling of cargo. Because a supercargo sails from port to port with the vessel to which he is attached, he differs from a factor, who has a fixed place of residence at a port or other trading place.
 Supercargo in history
 In literature
- Supercargo is a character in Ralph Ellison's Invisible Man. He is described as a large African-American male who works as an orderly. Supercargo watches over African-American World War I veterans who were traumatized by the stresses of war.
- In Robert Louis Stevenson's Treasure Island, Long John Silver refers to the main character as having 'slept like a supercargo.'
- In Alexandre Dumas, père's The Count of Monte Cristo, Danglars is supercargo of the ship of which Edmond becomes captain.
- In Ian Fleming's Thunderball James Bond recalls that he was a supercargo on a submarine during World War II
- In many of Louis Becke's Pacific Tales (1897), the supercargo Denison is the observer or hearer of the tale.
- Myron Tany is the supercargo in Ports of Call by Jack Vance.
- In the film, Captain Kidd and the Slave Girl, Eva Gabor is introduced to the supercargo and asks what he does; his role is explained to her.
- In Anne McCaffrey’s Crystal Singer, Pendel is the supercargo aboard the Trundimoux Cruiser, who provides assistance to Heptite Guild Member Killashandra Ree.
- In Flash for Freedom!, Harry Flashman is cajoled into being supercargo for his father in law to avoid a scandal.
- In Voyager, Jamie Fraser becomes the supercargo for his cousin Jared's ship Artemis on the voyage from France to the West Indies to find Ian Murray, Jamie's nephew.
 See also
- Loadmaster, a similar role for command personnel of a military cargo aircraft
- "DE LA PORTA BROTHERS". Texas State Historical Association. Retrieved 28 July 2011.