Metopus was a Pythagorean philosopher who lived during the Hellenistic period, likely in the 4th or 3rd century BCE. He is an extremely obscure figure, and no details about his personal life or birthplace are known. His existence is attested only by a brief mention in the writings of the much later philosopher Porphyry, who listed Metopus among the followers of Pythagoras. According to modern scholars, such lists often anachronistically grouped Pythagoreans from different centuries under the founder's name.

He is credited with a single work, a treatise titled On Virtue. This work is completely lost, surviving only as a title in Porphyry's catalog. No fragments or summaries of its content have been preserved.

Metopus's historical importance is minimal but specific. His sole attestation confirms he was remembered within the later Pythagorean tradition. The total loss of his writing means his particular ideas about virtue are unknown. He serves as a typical example of the many minor philosophers from antiquity whose names survive in lists, but whose works and thoughts have not endured.