Timaeus of Locri (called Timaeus Locrus in Latin, Timée de Locres in French) was a Pythagorean philosopher living in the 5th century BC.

He features in Plato's Timaeus, where he is said to come from Locri in Italy.

He also appears as one of the speakers in Plato's Critias.

Later references to Timaeus of Locri from Antiquity are by:

Cicero, in his De re publica (I, X, 16), where he is described as an intimate of Plato

Proclus, in his Commentary on Plato's Timaeus (II, 38, I)

Simplicius and Diogenes Laertius, in their descriptions of, and commentaries on Aristotle's work

All ancient references to him seem to have derived from Plato: he may well be a fictional character invented for the dialogue bearing his name.

References

Timæus Locrus, Fragmenta et testimonia (Fragments and testimonies), commentary by Matthias Baltes - Über die Natur des Kosmos und der Seele / Timaeus Locrus ; Brill, 1972, xii-252 p. Coll. « Philosophia Antiqua ».

Oxford Classical Dictionary, 2nd edition 1996: Timaeus

Timaeus Lunar Crater