Orestes (died 28 August 476) was a Roman general and politician of Pannonian ancestry, who was briefly in control of the remnant Western Roman Empire in 475 and 476.
Born to a Roman family from Pannonia Savia, Orestes was son of Tatulus, a pagan, and son-in-law to Romulus who served as comes in the Western Roman Empire. After Pannonia was ceded to Attila the Hun, Orestes joined Attila's court, reaching high position as a secretary (notarius) in 449 and 452. In 449, Orestes was sent by Attila twice to Constantinople as envoy to Emperor Theodosius II.
In 475, Orestes was appointed magister militum and patricius by Western Roman Emperor Julius Nepos. This proved to be a mistake on the part of Nepos. By August 28, 475, Orestes, at the head of the foederati levies, managed to take control of the government in Ravenna, which had been the de facto capital of the Western Roman Empire since 402. Julius Nepos fled without a fight to Dalmatia, where he would continue to reign until his assassination in 480. With the emperor far away, Orestes elevated his son Romulus to the rank of Augustus, so that the last Western Roman emperor is known as Romulus Augustulus meaning "little Augustus" as the emperor was only a 14-year-old boy.
The new administration was not recognized by the rival Eastern Roman Emperors Zeno and Basiliscus, who still considered Julius Nepos to be their legitimate partner in the administration of the Empire. But as they were engaged in a civil war with each other, neither emperor was about to oppose the latest usurper in battle.