Antonius Diogenes (Ancient Greek: Ἀντώνιος Διογένης) was the author of an ancient Greek romance entitled The Wonders Beyond Thule (Τὰ ὑπὲρ Θoύλην ἄπιστα Apista huper Thoulen). Scholars have placed him in the 2nd century CE, but his age was unknown even to Photios, who wrote a synopsis of the romance. The romance was a novel of twenty-four books and was written in the form of a dialogue about travels. It is highly praised by Photios for its vivid narration, its clearness, and the gracefulness of its descriptions.