Troilus and Cressida (play), play by English playwright William Shakespeare. Probably written in 1602, Troilus and Cressida is derived from a medieval legend about Troilus, son of King Priam of Troy, and Cressida, daughter of the Trojan soothsayer Calchas. Their love story was a popular theme that inspired many literary works, including a long poem by Geoffrey Chaucer, Troilus and Criseyde (1385?).

Troilus and Cressida is considered one of the most problematic of Shakespeare's plays, with critics arguing over its classification as a romantic tragedy, satire, or history. As the play opens, the Trojan War between the Greeks and the city of Troy has been going on for seven years. Troilus falls in love with Cressida, whose father has gone over to the Greek side. Their love affair is interrupted when she is given to the Greeks in exchange for a Greek prisoner. Cressida betrays Troilus with her Greek captor, Diomed. Troilus rushes into battle to avenge the death of his friend Hector and to kill Diomed. A cynical speech by Cressida’s uncle, Pandarus, ends the play on an inconclusive note.

In the development of the play’s theme, Shakespeare continues a convention followed since Chaucer's day and degrades Cressida into a worthless wanton who distributes her favors to Greek and Trojan alike. Troilus is equally flawed, idealizing his love for Cressida but expressing it only in terms of physical desire. The characters of the Greek and Trojan heroes are drawn in accordance with medieval conceptions rather than with the Homeric originals. One of the characters, Thersites, borrowed from Chapman's translation of the Iliad, is the most foul-mouthed rogue in any of Shakespeare's plays.

Troilus and Cressida is burdened with long philosophical and ethical harangues; some critics believe that its wordy prologue and epilogue may have been added separately. However, the play has passages of grave and noble poetry that skillfully evoke the gulf, both individual and political, between the ideal and the real.