Cressia (also Criseida, Cresseid or Criseyde) is a character who appears in many Medieval and Renaissance retellings of the story of the Trojan War. She is a Trojan woman, daughter of Calchas, who falls in love with one of the sons of King Priam, Troilus. She pledges everlasting love, but when she is sent to the Greeks as part of a hostage exchange, she forms a liaison with the Greek warrior Diomedes. The character's name is derived from that of Chryseis.