Philo of Byzantium was a Greek scientist and engineer active in the late third and early second centuries BCE during the Hellenistic period. He worked in major centers of learning such as Alexandria and Rhodes. He is best known for compiling a large, nine-part encyclopedia titled Mechanical Collection, which aimed to cover the entire field of ancient mechanics.

His surviving works focus on practical technology. The most influential is On Pneumatics, which describes devices powered by air, water, and steam, including pumps and automated toys. This work was later translated into Arabic and Latin, shaping engineering for centuries. Another important surviving text is Belopoeica, which provides detailed instructions for building catapults and marks a shift toward mathematically precise military designs. A section on building automated theaters, On Automata-Making, also survives. Unfortunately, most of his encyclopedia, including books on harbors, siegecraft, and stratagems, is lost.

According to modern scholars, Philo’s significance lies in his systematic effort to bridge theoretical knowledge and hands-on engineering. His surviving writings make him a crucial link between the innovations of earlier Alexandrian engineers and the technological traditions of the medieval and Renaissance worlds.