Ophelia (/oʊˈfiːliə/) is a character in William Shakespeare's drama Hamlet (1599–1601). She is a young noblewoman of Denmark, the daughter of Polonius, sister of Laertes and potential wife of Prince Hamlet. Due to Hamlet's actions, Ophelia ultimately becomes mad and drowns.

Ophelia, and Hamlet's mother, Queen Gertrude, are the only two female characters in the play.

Like most characters in Hamlet, despite the plot taking place in Denmark, Ophelia's name is not of Danish origin. It first appeared in Jacopo Sannazaro's 1504 poem Arcadia (as Ofelia), probably derived from Ancient Greek ὠφέλεια (ōphéleia, "benefit").

Ophelia is obedient to her father and well-loved by many characters. When Polonius tells her to stop seeing Hamlet, she does so. When he tells her to set up a meeting so that he and Claudius could spy on him, she does so. Ophelia is a foil to Hamlet and Laertes, contrasting and inspiring their behaviour.

In Ophelia's first speaking appearance in the play, she is seen with her brother, Laertes, who is leaving for France. Laertes warns her that Hamlet, the heir to the throne of Denmark, does not have the freedom to marry whomever he wants. Ophelia's father, Polonius, who enters while Laertes is leaving, also forbids Ophelia from pursuing Hamlet, as Polonius fears that Hamlet is not earnest about her.

In Ophelia's next appearance, she tells Polonius that Hamlet rushed into her room with his clothing askew and a "hellish" expression on his face; he only stared at her, nodding three times without speaking to her. Based on what Ophelia told him, Polonius concludes that he was wrong to forbid Ophelia from seeing Hamlet, and that Hamlet must be mad with love for her. Polonius immediately decides to go to Claudius, the new King of Denmark and also Hamlet's uncle and stepfather, about the situation. Polonius later suggests to Claudius that they hide behind an arras to overhear Hamlet speaking to Ophelia, when Hamlet thinks the conversation is private. Since Polonius is now sure that Hamlet is lovesick for Ophelia, he thinks Hamlet will express his love for her. Claudius agrees to try the eavesdropping plan later.

The plan leads to what is commonly called the "Nunnery Scene", from its use of the term nunnery which would generally refer to a convent, but at the time was also popular slang for a brothel. Polonius instructs Ophelia to stand in the lobby of the castle while he and Claudius hide. Hamlet approaches Ophelia and talks to her, saying "Get thee to a nunnery." Hamlet asks Ophelia where her father is; she lies to him, saying her father must be at home. Hamlet realises he is being spied upon. He exits after declaring, "I say we will have no more marriages." Ophelia is left bewildered and heartbroken, sure that Hamlet is insane. After Hamlet storms out, Ophelia makes her "O, what a noble mind is here o'erthrown" soliloquy.

The next time Ophelia appears is at the Mousetrap Play, which Hamlet has arranged to try to prove that Claudius killed King Hamlet. Hamlet sits with Ophelia and makes sexually suggestive remarks; he also says that woman's love is brief.