This book provides a translation of the only surviving ancient commentary on Plato's Gorgias, written by the Alexandrian Platonist Olympiodorus in the sixth century AD. There are substantial notes on the commentary, which assist the reader to understand the context of Olympiodorus' Platonism, the choices available to him as an interpreter, and the special characteristics of his interpretation. A substantial introduction tackles the issues of greatest interest that arise from the work, including the author's mission as a Hellenist resisting Christian attacks on his discipline. Indices are provided. The authors show that there is much more of value in this commentary than has often been supposed, and that the differences between Olympiodorus' approach and those of modern commentators are often illuminating.