Set in a 14th-century Renaissance Italy in varying locations:
- The balcony scene: At the Palazzo Borghese, built by Cardinal Scipione Borghese in the 16th century, in Artena, 20 miles south of Rome.
- The church scenes: At a Romanesque church named St. Pietro in Tuscania, 50 miles northwest of Rome.
- The tomb scene: Also in Tuscania.
- The palace of the Capulets' scenes: At Palazzo Piccolomini, built between 1459-62 by Pope Pius II, in the city of Pienza, in Siena province.
- The street scenes: Also in Pienza.
- The fight scenes: In Gubbio, a town in the region of Umbria.
According to Franco Zeffirelli's autobiography, Paul McCartney was originally asked to play the part of Romeo.
- Leonard Whiting as Romeo
- Olivia Hussey as Juliet
- John McEnery as Mercutio
- Milo O'Shea as Friar Lawrence
- Pat Heywood as The Nurse
- Robert Stephens as The Prince
- Michael York as Tybalt
- Bruce Robinson as Benvolio
- Paul Hardwick as Lord Capulet
- Natasha Parry as Lady Capulet
- Antonio Pierfederici as Lord Montague
- Esmeralda Ruspoli as Lady Montague
- Keith Skinner as Balthasar
- Roberto Bisacco as Paris
- Laurence Olivier as Chorus (uncredited)