Herodian (flourished 2nd century ad) was a Greek grammarian of Alexandria who is important primarily for his work on Greek accents.
A son of the grammarian Apollonius Dyscolus, Herodian settled in Rome under the emperor Marcus Aurelius, to whom he dedicated a treatise on accentuation and quantity entitled Katholikē prosōdia (“General Prosody”). Extracts from it survive. His Peri monerous lexeos (“On Anomalous Words”), a discourse in which he disputes his father’s position on analogy, survives complete, and the titles of about 30 other works by him are known, though only a few extracts from them survive. A number of spurious and doubtful works were also attributed to him.