Chimes at Midnight (Spanish: Campanadas a medianoche, released in most of Europe as Falstaff) is a 1966 period comedy-drama film written, directed by, and starring Orson Welles. Its plot centers on William Shakespeare's recurring character Sir John Falstaff and his fatherly relationship with Prince Hal, who must choose loyalty to Falstaff or to his actual father, King Henry IV. The English-language film was an international co-production of Spain, , and Switzerland.

Welles said that the core of the film's story was "betrayal of friendship". It stars Welles as Falstaff, Keith Baxter as Prince Hal, John Gielgud as Henry IV, Jeanne Moreau as Doll Tearsheet, and Margaret Rutherford as Mistress Quickly. The script contains text from five of Shakespeare's plays, primarily Henry IV, Part 1 and Henry IV, Part 2, but also Richard II, Henry V, and The Merry Wives of Windsor. Ralph Richardson's narration is taken from the works of chronicler Raphael Holinshed.

Welles had produced a Broadway stage adaptation of nine Shakespeare plays, Five Kings, in 1939. In 1960, he revived this project in Ireland as Chimes at Midnight, which was his final stage performance. Neither of these plays was successful, but Welles considered portraying Falstaff his life's ambition and turned the project into a film. To get financing, he lied to producer Emiliano Piedra that he intended to make a version of Treasure Island, and keeping the film funded during its production was a constant struggle. Welles shot Chimes at Midnight in Spain between 1964 and 1965; it premiered at the 1966 Cannes Film Festival, winning two awards there.

Initially dismissed by most film critics, Chimes at Midnight is now regarded as one of Welles's highest achievements, and Welles called it his best work. Welles felt a strong connection to the character of Falstaff and called him "Shakespeare's greatest creation". Some film scholars and Welles's collaborators have made comparisons between Falstaff and Welles, while others see a resemblance between Falstaff and Welles's father. Disputes over the ownership of Chimes at Midnight made it difficult to view the film legally until recently. It was released in the UK on DVD and Blu-ray in 2015. A new restoration by Janus Films and The Criterion Collection screened at Film Forum in New York on January 1–12, 2016. The Criterion Collection released the film on Blu-ray and DVD on August 30, 2016.