Cynegeirus or Cynaegeirus or Cynegirus (, ?-490 BC) was an ancient Greek hero of Athens and had three siblings. His two brothers were the playwright Aeschylus and the hero of the battle of Salamis Ameinias, and his sister was Philopatho (), who was the mother of the Athenian tragic poet Philocles. At Elefsina there is a monument dedicated to him.