Philo of Tarsus was a physician from the city of Tarsus in Cilicia, active during the Hellenistic period, likely in the 1st century BCE or 1st century CE. He is known only from later medical sources, which sometimes mention him alongside figures like Heraclides of Tarentum. No details of his personal life or education survive.

His sole attested work is a pharmacological treatise titled On the Powers and Mixtures of Simple Drugs. The text is lost but is preserved in fragments cited by later medical authorities, notably Scribonius Largus and Galen. Galen references Philo’s opinions on specific drugs, such as the root of the "all-heal" plant.

Philo represents the Hellenistic empirical tradition of materia medica. His significance lies in his role as a pharmacological source for later Roman medicine; Galen engages with his doctrines, demonstrating Philo’s continued relevance in professional debates.