A messenger brings news to Leonato, the governor of Messina, that his friend Don Pedro is returning home from war with his soldiers, including Benedick and the ‘brave’ Claudio. Leonato lives with his daughter, Hero, and his niece, Beatrice. Beatrice asks about Benedick, whom she openly mocks, but the messenger defends the soldier’s reputation.

Don Pedro and his men arrive at Leonato’s house and are greeted as guests. Beatrice taunts Benedick immediately and the two begin their 'merry war', teasing each other and exchanging insults.

The young Claudio catches sight of Hero and instantly falls in love. He declares his feelings to Benedick who, stinging from Beatrice’s insults, is horrified his friend might marry. Don Pedro enters and agrees to use his influence to woo Hero on Claudio’s behalf and arrange the marriage with her father.

Antonio, Leonato’s older brother, finds out that Don Pedro and Claudio have been overheard talking about Hero. He misinterprets this and tells Leonato that Don Pedro is in love with Hero and intends to woo her that evening.

Don John, the illegitimate brother of Don Pedro, reveals his bitterness towards his brother and his jealousy of Claudio. He immediately plans to ruin things for Claudio, with help from his follower Borachio.

After supper, Beatrice mocks Don Pedro and Benedick. Leonato warns her that such an attitude will not get her a husband but Beatrice claims that she is happy to stay single and gives advice to Hero on the importance of thinking for herself.

Leonato throws a masked ball for his family and guests. Don John tells Claudio that Don Pedro plans to woo Hero for himself at the party. Claudio believes this and complains to Benedick. The prince is quick to set things right when he learns and Claudio and Hero are engaged. Benedick teases Beatrice while masked, but she gets the better of him. Don Pedro decides to trick them both and bring them together and Hero, Claudio and Leonato agree to help.

Don John is looking for ways to ruin Claudio’s wedding to Hero. His follower Borachio has a plan: Borachio will arrange to be seen with Hero’s waiting woman Margaret, at Hero’s bedroom window, and Claudio will mistake Margaret for Hero and think Hero is being unfaithful. Borachio claims this will hurt Don Pedro, Claudio, Hero and Leonato in one go. Don John says he’ll pay Borachio for his cunning.

In a soliloquy, Benedick talks about how unlikely it is he’ll ever fall in love like Claudio. Benedick hides when he sees Don Pedro, Claudio and Leonato approaching. The men pretend not to see him and talk about how Beatrice is madly in love with Benedick but too afraid to tell him. They list Beatrice’s good points and worry that Benedick will mock her if he knows. Afterwards, Benedick vows to return Beatrice’s love.

Hero arranges that Beatrice overhears a conversation between herself and Ursula where they are talking about her. When Beatrice hides, the women start talking about Benedick’s love for Beatrice but how Beatrice is too proud and would mock him if she knew. They list Beatrice’s bad points and praise Benedick. Left alone, Beatrice is ashamed at how she’s been described and promises to return Benedick’s love.

Don John tells Don Pedro and Claudio he has proof that Hero is unfaithful. Claudio and Don Pedro follow him, saying they will shame Hero publicly if it’s true.

Near Leonato’s house, a Constable called Dogberry gives comically unclear instructions to his confused Watch. After he leaves, a drunken Borachio enters and brags to Conrad about how he deceived Don Pedro and Claudio. The Watch overhear and arrest the villains.

Hero is dressing for her wedding. Her waiting woman, Margaret, teases her about her wedding night. Beatrice enters, suffering from a bad cold. Margaret suggests she’s lovesick and teases her about Benedick. Ursula enters, with news that the men have arrived to take Hero to the church.

Leonato is busy with last-minute wedding plans. Dogberry and Verges arrive to tell him about Borachio’s arrest but Dogberry takes so long to explain himself that Leonato loses patience. He tells Dogberry to go ahead with the trial, without realising that the crime involves his daughter.

Claudio rejects Hero at the altar. Hero denies being unfaithful and faints when Don Pedro confirms he saw her as well. Don Pedro, Don John and Claudio leave and Leonato refuses to believe his daughter and wishes her dead. Beatrice and the Friar, along with Hero herself, maintain she was faithful. The Friar then advises them to pretend she is dead until her innocence is proved.

Alone together in the church, Beatrice and Benedick admit their love for each other. Beatrice asks Benedick to 'kill Claudio’ for what he has done to her cousin and wishes she was a man so she could do it herself. Benedick eventually agrees to challenge Claudio.

In a courtroom, Dogberry and the Sexton clumsily take evidence from Borachio and Conrad. The Watch confirm they heard Borachio confess his crime. The Sexton reveals that Hero has died and Don John has run away. The prisoners are taken away and Conrad insults Dogberry.

Antonio tries to comfort Leonato. Claudio enters with Don Pedro and Leonato accuses him of killing his daughter. When Leonato and Antonio leave, Benedick enters and also challenges Claudio for causing Hero’s death. After Benedick leaves, the Watch bring in Borachio who confesses his crime and clears Hero’s name. At Leonato’s orders, Claudio goes to Hero’s tomb and agrees to marry a daughter of Antonio’s who looks like Hero.

Benedick asks Margaret to arrange a meeting with Beatrice. As he waits, he reveals his poor attempts to write a love poem. When Beatrice arrives, he says he has challenged Claudio and asks how she first fell in love with him. Beatrice asks the same of him. As they talk, Ursula rushes in with news of Don John’s plot and all three leave for Leonato’s house.

In a solemn ceremony, Claudio keeps the first part of his promise to Leonato. At Hero’s monument, an epitaph to Hero is read out, a hymn is sung and a vow made to remember the anniversary of her death. Don Pedro and Claudio leave to dress for Claudio’s wedding to Hero’s ‘cousin’.

Margaret’s name is cleared. Leonato tells Hero, Beatrice, Margaret and Ursula to put on veils in order to confuse Claudio. The veiled women enter and Claudio accepts his unknown bride. Hero is revealed and she and Claudio are reunited. Beatrice and Benedick realise they have been tricked into revealing their love to one another but still agree to marry, as news arrives that Don John has been captured.