Astydamas the Younger was an Athenian tragic poet of the 4th century BCE. He was the son of the tragedian Astydamas the Elder and the grandson of Philocles, a nephew of Aeschylus, placing him within a distinguished dramatic lineage. A contemporary of Demosthenes, he was noted for his exceptional pride; ancient sources record that he erected a statue of himself in the Theatre of Dionysus, an act met with public ridicule.

He was a prolific and successful playwright, credited with 240 tragedies and satyr plays, of which 15 won first prize. His surviving works exist only in fragments. Known titles include Achilles, Athamas, Antigone, Hector, and Heracles. He achieved a notable victory in 340 BCE for a production featuring Achilles, Athamas, and Antigone.

Astydamas represents the generation of tragedians following the 5th-century masters. His career demonstrates the continued vitality of Athenian tragic theatre in the Classical period beyond Sophocles and Euripides. The anecdote of his statue became a proverbial example of artistic vanity in antiquity.