Theophilus the Historian (Θεόφιλος ὁ Ἱστορικός) was a 4th-century BCE author known solely for a single historical work. No biographical details survive beyond this attribution [1].

His only known work is On Sicily (Περὶ Σικελίας), a lost history focusing on Sicilian affairs. It survives only in fragments and testimonia, referenced in the Suda lexicon and by later authors like Athenaeus [1][2].

Theophilus is a minor fragmentary historian. His significance lies in his role as a source for regional history; later authors cite On Sicily for details on Sicilian geography, customs, and figures, such as the luxurious habits of the Sybarites [2]. He is often grouped with other local historians of Sicily like Antiochus of Syracuse [1].

Sources 1. Perseus Digital Library (Tufts University): http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Qeofilos 2. ToposText (Aikaterini Laskaridis Foundation): https://topostext.org/people/1500