Olympiodorus was an historical writer and notable astrologer (5th century AD), born at Thebes in Egypt, who was sent on a mission to the Huns on the Black Sea by emperor Honorius in 412, and later lived at the court of Theodosius. The record of his diplomatic mission survives in a single epitome:

Donatus and the Huns, and the skillfulness of their kings in shooting with the bow. The author relates that he himself was sent on a mission to them and Donatus, and gives a tragic account of his wanderings and perils by the sea. How Donatus, being deceived by an oath, was unlawfully put to death. How Charaton, the first of the kings, being incensed by the murder, was appeased by presents from the emperor.

— from Photius' Bibliotheca, tr. J.H. Freese

He was the author of a history in 22 books of the Western Empire from 407 to 425. The original is lost, but an abstract is given by Photius, according to whom he was an alchemist. A manuscript treatise on alchemy, reputed to be by him, is preserved in the National Library in Paris, and was printed with a translation by Berthelot in his Collection des alchimistes grecs (1887–1888).