Alain Alivon, known under the pseudonym Marius (born 23 July 1965 in Marseille), is a French military and drill instructor member of the Commandos Marine unit and the French Navy. He is mostly known for featuring in the 2005 documentary L'École des bérets verts on France 2 in the program Envoyé spécial. He later appeared on film and television, and publishing his autobiography.

Alain Alivon spent a difficult childhood at the public assistance of Marseille, and a delinquent teenager in the North Quarter of Marseille and Vitrolles. He studied law but gave up soon after and committed offences with bad frequentations of the period. After a tough custody at the police station, a police officer recommended him to start his military service, giving him a chance to go through ("an intelligent person who knew how to talk to me respectfully, giving me the good tools").