Julius Valerius Majorianus (c. 420 - November, 461), commonly known as Majorian, was Western Roman Emperor (457 - 461).

He had distinguished himself as a general by victories over the Franks and Alemanni, and six months after the deposition of Avitus he was declared emperor by the regent Ricimer.

After repelling an attack by the Vandals upon Campania in 458 he prepared a large force, composed chiefly of Germans, to invade Africa, which he previously visited in disguise.

Having during his stay in Gaul defeated Theodoric the Visigoth and then concluded an alliance with him, at the beginning of 460 he crossed the Pyrenees with the purpose of joining the powerful fleet which he had collected at Cartagena. The Vandal king Genseric, however, after all overtures of peace had been rejected, succeeded through the treachery of certain officers in surprising the Roman fleet, most of the ships being either taken or destroyed.

Majorian thereupon made peace with Genseric. But his ill-success had destroyed his military reputation; his efforts to put down abuses and improve the condition of the people had roused the hatred of the officials; and Ricimer, jealous of his fame and influence, stirred up the foreign troops against him.

A mutiny broke out in Lombardy, and on the August 2, 461 Majorian was forced to resign by Ricimer. He died five days afterwards, either of dysentery or by violence.

Majorian was the author of a number of remarkable laws, contained in the Codex Theodosianus. He remitted all arrears of taxes, the collection of which was for the future placed in the hands of the local officials. He revived the institution of defensores or administrators of cities, whose duty it was to protect the poor and inform the emperor of abuses committed in his name. The practice of pulling down the ancient monuments to be used as building material, which was connived at by venal officials, was strictly prohibited. He also passed laws against compulsory ordination and premature vows of celibacy.