Brontinus of Metapontum (Greek: Βροντῖνος, also Brotinus, Βροτῖνος; fl. 6th century BCE), Magna Graecia, was a Pythagorean philosopher and a friend and disciple of Pythagoras. Alcmaeon dedicated his works to Brontinus as well as to Leon and Bathyllus.^[1] Accounts vary as to whether he was the father or the husband of Theano.^[2]

Some Orphic poems were ascribed to Brontinus. One was a poem On Nature (Physika),^[3] another was a poem called The Robe and the Net^[3] that was also ascribed to Zopyrus of Heraclea.^[4]

His fame was sufficient for a spurious work to be ascribed to him in the Neopythagorean literature. Syrianus (5th century CE) refers to "Brotinus"^[5] as an author of the view that the monad, or first cause, "transcends all kinds of reason and essence in power and dignity,"^[6] whereby an attempt was made to insert an element of Platonism into Pythagoreanism,^[7] which probably refers to Neoplatonism.