Basilis the Historian is a Hellenistic figure dated to the 3rd–2nd century BCE. No biographical details are recorded. The name "Basilis" appears in ancient sources, but refers to mythological figures such as a daughter of the river god Maeander or an early Arcadian king, not to this historian.

A single historical work is attributed to him, but its title and content are unknown. The name is absent from records of Hellenistic historiography. A later Christian author, Basilius of Caesarea, is a major figure but is unrelated.

Basilis the Historian holds no established significance. He is not cited by later ancient historians and is absent from standard references on Hellenistic historiography, suggesting he is an obscure figure possibly known only from a single unverified fragment.