Sosthenes of Cnidus was a Greek historian known only from a single citation by the Roman author Aulus Gellius. He was active in the 4th century BCE, as his work concerned Philip II of Macedon.

His sole attested work is the lost History of Philip, referenced in Aulus Gellius' Attic Nights. No fragments or descriptions of its content are extant.

Sosthenes is a minor figure, significant only as one of several lost historians who documented the rise of Macedon under Philip II. His work would have offered a contemporary perspective, but its complete loss prevents any assessment of its historical value or style.