One summer morning in Verona, Veneto, a longstanding feud between the Montague and the Capulet clans breaks out in a street brawl. The brawl is broken up by the Prince, who warns both families that any future violence between them will result in harsh consequences. That night, two teenagers of the two families — Romeo and Juliet — meet at a Capulet masked ball and become deeply infatuated. Later, Romeo stumbles into the secluded garden under Juliet's bedroom balcony and the two exchange impassioned pledges. They are secretly married the next day by Romeo's confessor and father figure, Friar Laurence, with the assistance of Juliet's nursemaid.
That afternoon, Juliet's first cousin Tybalt, enraged that Romeo had attended his family's ball, insults him and challenges him to a brawl. Romeo regards Tybalt as family and he refuses to fight him, which leads Romeo's best friend, Mercutio, to fight Tybalt instead. Despite Romeo's efforts to stop the fight, Tybalt badly wounds Mercutio, who curses both the Montague and Capulet houses before dying. Enraged over his friend's death, Romeo retaliates by fighting Tybalt and killing him. Romeo is subsequently punished by the Prince with banishment from Verona, with the threat of death if he ever returns. Romeo, however, sees his banishment as worse than the death penalty, as Verona is the only home he has known and he does not want to be separated from Juliet. Friar Laurence eventually convinces Romeo that he is very lucky and that he should be more thankful for what he has. Romeo then secretly spends his wedding night together with Juliet and the couple consummate their marriage before Romeo flees.
Juliet's father and mother, unaware of their daughter's secret marriage, have arranged for Juliet to marry wealthy Count Paris. Juliet pleads with her parents to postpone the marriage, but they refuse and threaten to disown her. Juliet seeks out Friar Laurence for help, hoping to escape her arranged marriage to Paris and remain faithful to Romeo. At Friar Laurence's behest, she reconciles with her parents and agrees to their wishes. On the night before the wedding, Juliet consumes a potion prepared by Friar Laurence intended to make her appear dead for forty-two hours. Friar Laurence plans to inform Romeo of the hoax so that Romeo can meet Juliet after her burial and escape with her when she recovers from her swoon, so he sends Friar John to give Romeo a letter describing the plan. However, when Balthasar, Romeo's servant, sees Juliet being buried under the impression that she is dead, he goes to tell Romeo and reaches him before Friar John. In despair, Romeo goes to Juliet's tomb and kills himself by drinking poison. Soon afterwards, Juliet awakens and discovers her husband dead. Juliet refuses to leave Romeo and kills herself by piercing her abdomen with his dagger. Later, the two families attend their joint funeral and are chastised by the Prince.