Brother Sun, Sister Moon (Italian: Fratello sole, sorella luna) is a 1972 historical drama film based on the hagiography of Saint Francis of Assisi. It is directed by Franco Zeffirelli from a screenplay he co-wrote with Suso Cecchi d'Amico, Lina Wertmüller and Kenneth Ross. It stars Graham Faulkner as Francis and Judi Bowker as Clare of Assisi, along with Leigh Lawson, Kenneth Cranham, Lee Montague, Valentina Cortese and Alec Guinness. The title of the film is from Francis' "Canticle of the Sun."

A co-production of Italy and the United Kingdom, the film premiered on March 3, 1972. It is also known for its song score by musician Donovan, which were later released as his 22nd studio album in 2004. The film received mixed reviews from critics, but was nominated for an Academy Award for Best Production Design and a BAFTA Award for Best Costume Design.