The ancient scholia to Sophocles' Oedipus at Colonus shed light on Alexandrian ways of engaging with this play, and are richer than those to the other Sophoclean plays. The last editor, Vittorio de Marco (1952), established a better text of these scholia than his predecessors, in as much as he had a fuller knowledge of their manuscript tradition and a better understanding of their stratified nature. Still, his work is marred by a number of inaccuracies, omissions and methodological shortcomings. The new edition by Georgios Xenis improves on de Marco's work by a careful examination of all the sources of the text and the conjectures proposed by scholars, and by relying on a clearly defined methodological framework. In this edition the scholia to the Oedipus at Colonus are restored in a textual state that is arguably the earliest we can recover, and is free of contradictions, unacceptable repetitions, and hybridisation or blending of elements from different versions. The critical text is accompanied by a detailed apparatus criticus, and is contextualised in its ancient scholarly tradition by means of a rich array of passages drawn from comparable sources. Extensive indices are provided at the end of the volume. The edition will be an invaluable resource for those engaged in the interpretation of Sophocles' tragedies and, in particular, of the Oedipus at Colonus, and will be of interest to classicists working on ancient literary criticism and ancient scholarship.