Lucius Annaeus Cornutus (fl. 60s AD; Ancient Greek: Λεύκιος Ἀνναῖος Κορνοῦτος) was a Stoic philosopher who flourished in the reign of Nero, when his house in Rome was a school of philosophy.

Cornutus was a native of Leptis Magna in Libya, but resided for the most part in Rome. He is best known as the teacher and friend of Persius, whose fifth satire is addressed to him, as well as other distinguished students, such as Claudius Agathemerus. "Through Cornutus Persius was introduced to Annaeus, as well as to Lucan, who was of his own age, and also a disciple of Cornutus". At Persius's death, Cornutus returned to Persius' sisters a bequest made to him, but accepted Persius' library of some 700 scrolls. He revised the deceased poet's satires for publication, but handed them over to Caesius Bassus to edit, at the special request of the latter.

Among Persius's satires were lines that, as Suetonius records, "even lashed Nero himself, who was then the reigning prince. The verse ran as follows:

but Cornutus altered it to:

in order that it might not be supposed that it was meant to apply to Nero."

Annaeus Cornutus was banished by Nero nevertheless – in 66 or 68 AD – for having indirectly disparaged the emperor's projected history of the Romans in heroic verse, after which time nothing more is heard of him.

He was the author of various rhetorical works in both Greek and Latin, such as De figuris sententiarum. Excerpts from his treatise De enuntiatione vel orthographia are preserved in Cassiodorus. A commentary on Virgil is frequently quoted by Servius, but tragedies mentioned by Suetonius have not survived.

Cornutus wrote a work on Rhetoric, and a commentary on the Categories of Aristotle, (πρὸς Ἁθηνόδωρον καὶ Ἀριστοτέλην) whose philosophy he attacked along with his fellow Stoic Athenodorus. He also wrote a work called On Properties (Περὶ ἐκτῶν).