Favorinus (c. 80 – c. 160 AD) was a Roman sophist and skeptic philosopher who flourished during the reign of Hadrian and the Second Sophistic.
He was of Gaulish ancestry, born in Arelate (Arles). He received a refined education, first in Gallia Narbonensis and then in Rome, and at an early age began his lifelong travels through Greece, Italy and the East.
Favorinus had extensive knowledge, combined with great oratorical powers, that raised him to eminence both in Athens and in Rome. He lived on close terms with Plutarch, with Herodes Atticus, to whom he bequeathed his library in Rome, with Demetrius the Cynic, Cornelius Fronto, Aulus Gellius, and with the emperor Hadrian. His great rival was Polemon of Smyrna, whom he vigorously attacked in his later years. He knew Greek very well.
After being silenced by Hadrian in an argument in which the sophist might easily have refuted his adversary, Favorinus subsequently explained that it was foolish to criticize the logic of the master of thirty legions. When the Athenians, feigning to share the emperor's displeasure with the sophist, pulled down a statue which they had erected to him, Favorinus remarked that if only Socrates also had had a statue at Athens, he might have been spared the hemlock.
Hadrian banished Favorinus at some point in the 130s, to the island of Chios. Rehabilitated at the ascension of Antoninus Pius in 138, Favorinus returned to Rome, where he resumed his activities as an author and teacher of upper-class pupils. Among his students were Alexander Peloplaton, who would later teach and serve under Marcus Aurelius, and Herodes Atticus, who also taught Marcus Aurelius and to whom Favorinus bequeathed his library. His year of death is unknown, but he appears to have survived into his eighties, and died perhaps around 160 AD.
Lucian's the Eunuch was probably modeled on Favorinus. Hofeneder and Amato also suggest that Favorinus is identical with the "Celtic philosopher" who explains the image of Ogmios in Lucian's Hercules.