Simplicius of Cilicia was a Neoplatonic philosopher who lived during the 6th century CE, a period of transition in the late ancient world. He studied in Alexandria and later in Athens, where he became part of a circle of pagan philosophers. This group faced significant pressure after the Christian Emperor Justinian issued an edict in 529 that restricted pagan teaching. According to historical accounts, Simplicius and several colleagues sought temporary refuge at the court of the Persian King Khosrow I. A peace treaty later guaranteed their safe return to the Eastern Roman Empire, though the exact location where he spent his later years is unknown.

He is renowned for writing extensive and detailed commentaries on the works of Aristotle. His major surviving works include commentaries on Aristotle's Categories, Physics, On the Heavens, and On the Soul. He also produced a commentary on the Handbook of the Stoic philosopher Epictetus. These writings are not simple explanations but are comprehensive scholarly works.

Modern scholars regard Simplicius as a figure of immense importance, primarily for his role as a preserver of earlier philosophical thought. His commentaries quote extensively from many earlier Greek thinkers, including Pre-Socratic philosophers and other schools, whose original works are now lost. This makes his writings an indispensable source for reconstructing the history of philosophy and science. Furthermore, his work represents a late Neoplatonic synthesis that sought to harmonize Aristotle with Plato. Through Byzantine, Arabic, and later Renaissance channels, his commentaries were instrumental in transmitting Aristotelian ideas to later intellectual traditions.