During the late Middle Ages in Verona, two wealthy families, the Montagues and Capulets, have been feuding for centuries. One day at the market place, the feuding families start a brawl which infuriates the Prince and he threatens that if the peace of Verona is disturbed again, he shall take their lives. Meanwhile, Romeo, a young Montague, reveals that he is in love with Lord Capulet's niece, Rosaline. Romeo's cousin, Benvolio persuades him to forget Rosaline but Romeo rebuffs him.
Later that night, there is a party held by Lord Capulet. Romeo sneaks in with Benvolio and Mercutio hoping to meet Rosaline. Instead, Romeo sees Juliet who is Lord Capulet's daughter and falls in love with her. Juliet feels the same and they share a dance. They go together to a quiet place and share a passionate kiss. Juliet's Nurse interrupts and when Romeo talks to the nurse, he discovers that Juliet is a Capulet.
After the party ends, Romeo sneaks into Juliet's garden secretly where he witnesses Juliet expressing her love for Romeo. They have a romantic time and decide to get married the next day. Romeo seeks help from Friar Laurence to wed them and the Friar agrees thinking that their love may end the violent war between Capulets and Montagues. They perform the ceremony and afterwards Juliet returns home. Romeo catches up with Mercutio and Benvolio but they meet Tybalt and his men on the way. This starts another violent brawl during which Tybalt stabs Mercutio. Romeo is enraged and runs after Tybalt seeking revenge. They fight and Romeo slays Tybalt. As the result of this loss, the Prince banishes Romeo from Verona.
Meanwhile both families are filled with grief over their losses, especially Juliet. The Friar sends Romeo to Juliet so he can spend one last night with her. Romeo goes to Juliet and they consummate their marriage. Romeo leaves in haste the next morning. But Juliet is shocked when her father brings news of planning to wed Juliet with Count Paris. Juliet is resistant but her father threatens to disown her if she does not wed Paris. Juliet goes to Friar Laurence for help, threatening to take her life if the Friar does not have a solution. The Friar in return, gives her a potion that will put her in a deathlike sleep temporarily while he will inform Romeo about this and they shall run away together. Juliet is overjoyed and drinks the potion that night. Her parents are devastated and instead of her marriage, her funeral is planned. During the funeral, Benvolio sees Juliet and thinks she is dead and immediately runs off to tell Romeo.
Friar's letter however, does not reach Romeo and Benvolio tells Romeo that Juliet is dead. Romeo is shocked and devastated and plans to take his life. He buys poison and goes to Juliet. He kisses Juliet one last time, then he drinks the potion unaware that Juliet has awakened. Juliet is overjoyed to see him and they kiss but Romeo suddenly collapses and she finds out that he took poison and Romeo dies in her arms. The Friar arrives but he is too late. He hears some guards coming and goes to hold them off. While Juliet is filled with grief, she finds and stabs herself with Romeo's dagger. The Friar arrives and finds them both dead.
Their funeral is held together and the feud between Capulets and Montagues finally reconcile, ending their feud.
- Douglas Booth as Romeo Montague
- Hailee Steinfeld as Juliet Capulet
- Damian Lewis as Lord Capulet
- Kodi Smit-McPhee as Benvolio Montague
- Ed Westwick as Tybalt
- Paul Giamatti as Friar Lawrence
- Lesley Manville as Nurse
- Christian Cooke as Mercutio
- Stellan Skarsgård as Prince Escalus of Verona
- Natascha McElhone as Lady Capulet
- Tom Wisdom as Count Paris
- Leon Vitali as Apothecary
- Laura Morante as Lady Montague
- Nathalie Rapti Gomez as Rosaline Capulet
- Tomas Arana as Lord Montague
- Simona Caparrini as a female guest
- Anton Alexander as Abraham (House of Montague)