Artemidorus (Ancient Greek: Ἀρτεμίδωρος) was a grammarian of ancient Greece who lived around the late 3rd and early 2nd centuries BCE. He was often called Aristophanius or Pseudo-Aristophanius owing to his having been a disciple of Aristophanes of Byzantium, the celebrated Librarian of Alexandria, as well as of Aristophanes's successor, Aristarchus of Samothrace.
His works are sometimes confused with those of another grammarian named Artemidorus, Artemidorus of Tarsus, who sometimes wrote about the playwright Aristophanes.