Megasthenes (c. 350 – c. 290 BC) is an ancient Greek historian, diplomat and Indian ethnographer and explorer in the Hellenistic period, author of the work Indika.

He is born in Asia Minor and becomes an ambassador of Seleucus I Nicator of the Seleucid dynasty possibly to Chandragupta Maurya in Pataliputra, India.

However, the exact date of his embassy is uncertain.

Scholars such as Kaushik Roy place him in the Maurya court between 302 and 298 BCE, prior to Chandragupta's voluntary death in 297.