Aedesius (Ancient Greek: Αιδέσιος, died 355) was a Neoplatonist philosopher and mystic born of a noble Cappadocian family.

He migrated to Syria, attracted by the lectures of Iamblichus, of whom he became a follower. According to Eunapius, he differed from Iamblichus on certain points connected with theurgy and magic. After the death of his master the school of Syria was dispersed, and Aedesius seems to have modified his doctrines out of fear of Constantine, and took refuge in divination.

An oracle in hexameter verse represented a pastoral life as his only retreat, but his disciples, perhaps calming his fears by a metaphorical interpretation, compelled him to resume his instructions.

He settled at Pergamum, where he numbered among his pupils Eusebius of Myndus, Maximus of Ephesus, and the emperor Julian. After the accession of the latter to the imperial purple he invited Aedesius to continue his instructions, but the declining strength of the sage being unequal to the task, two of his most learned disciples, Chrysanthius and the aforementioned Eusebius, were by his own desire appointed to supply his place.