Cressida is the fourth moon in order of distance from Uranus. It is named after the daughter of Calchas, a character in Shakespeare's play Troilus and Cressida and is also known as Uranus IX. Cressida was discovered by Stephen P. Synnott from images sent back by Voyager 2 on 9 January 1986, and was given the temporary designation S/1986 U3.