The Tragical History of Hamlet, Prince of Denmark is a tragedy by William Shakespeare. The play, set in the Kingdom of Denmark, recounts how Prince Hamlet exacts revenge on his uncle Claudius, firstly for murdering the old King Hamlet (Claudius's brother and Prince Hamlet's father) and secondly for then succeeding to the throne and marrying Gertrude (King Hamlet's widow and mother of Prince Hamlet). The play vividly portrays real and feigned madness – from overwhelming grief to seething rage – and explores themes of treachery, revenge, incest, and moral corruption.

Three different early versions of the play have survived: these are known as the First Quarto (Q1), the Second Quarto (Q2) and the First Folio (F1). Each has lines, and even scenes, that are missing from the others. Shakespeare based Hamlet on the legend of Amleth, preserved by 13th-century chronicler Saxo Grammaticus in his Gesta Danorum as subsequently retold by 16th-century scholar François de Belleforest. He may have also drawn on, or perhaps written, an earlier (hypothetical) Elizabethan play known today as the Ur-Hamlet.