Aristophanes of Byzantium (Greek: Ἀριστοφάνης ὁ Βυζάντιος; c. 257 – c. 185/180 b.c.) was a Hellenistic Greek scholar, critic and grammarian, particularly renowned for his work in Homeric scholarship, but also for work on other classical authors such as Pindar and Hesiod. Born in Byzantium about 257 b.c., he soon moved to Alexandria and studied under Zenodotus, Callimachus, and Dionysius Iambus. He succeeded Eratosthenes as head librarian of the Library of Alexandria at the age of sixty.
Aristophanes was the first to deny that the Precepts of Chiron was the work of Hesiod.
Aristophanes is credited with the invention of the accent system used in Greek to designate pronunciation, as the tonal, pitched system of archaic and classical Greek was giving way (or had given way) to the stress-based system of koine. This was also a period when Greek, in the wake of Alexander's conquests, was beginning to act as a lingua franca for the Eastern Mediterranean (replacing various Semitic languages). The accents were designed to assist in the pronunciation of Greek in older literary works.
He also invented one of the first forms of punctuation in ca. 200 b.c.; single dots (théseis, Latin distinctiones) that separated verses (colometry), and indicated the amount of breath needed to complete each fragment of text when reading aloud (not to comply with rules of grammar, which were not applied to punctuation marks until thousands of years later). For a short passage (a komma), a stigmḕ mésē dot was placed mid-level (·). This is the origin of the modern comma punctuation mark, and its name. For a longer passage (a kolon), a hypostigmḗ dot was placed level with the bottom of the text (.), similar to a modern colon or semicolon, and for very long pauses (periodos), a stigmḕ teleía point near the top of the line of text (·).
As a lexicographer he compiled collections of archaic and unusual words. He died in Alexandria around 185–180 b.c.. His students included Callistratus, Aristarchus of Samothrace, and perhaps Agallis.
All that has survived of Aristophanes of Byzantium's voluminous writings are a few fragments preserved through quotation in the literary commentaries, or scholia, of later writers, several argumenta to works of Greek drama, and part of a glossary. The most recent edition of the extant fragments was edited by William J. Slater.