Eparchius Avitus (c. 390 – 457) was Roman emperor of the West from July 455 to October 456. He was a senator of Gallic extraction and a high-ranking officer both in the civil and military administration, as well as Bishop of Piacenza.

He opposed the reduction of the Western Roman Empire to Italy alone, both politically and from an administrative point of view. For this reason, as Emperor he introduced several Gallic senators in the Imperial administration; this policy, however, was opposed by the senatorial aristocracy and by the people of Rome, who had suffered from the sack of the city by the Vandals in 455.

Avitus had a good relationship with the Visigoths, in particular with their king Theodoric II, who was a friend of his and who acclaimed Avitus Emperor. The possibility of a strong and useful alliance between the Visigoths and Romans faded, however, when Theodoric invaded Hispania at Avitus' behest, which rendered him unable to help Avitus against the rebel Roman generals who deposed him.