To the wider audience, John Williams is firmly associated with the string of dramas and fantasy/adventure films he scored for Steven Spielberg, or with the fairy tale/sci-fi Star Wars saga. More knowledgeable connoisseurs are also aware of his association in the 1970s with some of the most successful disaster movies of the decade—The Towering Inferno, Earthquake, The Poseidon Adventure, etc. Yet, Williams has also been substantially active in comedy, but the main scholarly literature on the composer has largely overlooked this aspect. Williams’s first landmarks in feature film scoring were in the comedy genre, back in the 1960s. Williams has also shown, throughout his production, a consistent presence of humorous touches and musical irony, whenever storytelling would allow for an appropriate presence. Williams’s concert music also presents traits of musical humour delivered through Prokofiev-like angular melodies, or extreme-range instrumental doublings (e.g. the tuba and the piccolo or the oboe), or unexpected harmonic twists. This chapter explores the comedic side of Williams’s music both in comedy and non-comedy cinema. The first part surveys the composer’s film production in the decades 1960s and 1970s, with a focus on his early career writing for the comedy genre and, later, on the subtler humorous touches in otherwise non-comic films. The second part deals with the post-1980 scores, demonstrating how instrumentation, harmonic language and rhythm, unusual timbres and idioms, and dissociations between music and the on-screen action create humorous touches and act as moments of comic relief or commentary within otherwise ‘serious’ films.