"Mighty Bruins" is a fight song of University of California, Los Angeles sports teams. Composed by Academy Award-winning composer Bill Conti (with lyrics from UCLA students Barbara Lamb and Don Holley), the song was commissioned by the UCLA Alumni Association on its fiftieth anniversary. It debuted in 1984 at the football game against Stanford University, with the school marching band conducted by Conti himself.
UCLA uses the song as its "victory march"; it is usually played whenever the team scores. As with UCLA's other fight song, Bruin Warriors, the Mighty Bruins prominently features the UCLA Eight Clap cheer.
One of the reasons for commissioning the song was to give UCLA its own fight song, separate from the University of California, Berkeley. UCLA has used Sons of Westwood, taken from the Cal Big C tune, as its best known fight song since the All-California football weekends.
Another of the reasons for the commissioning was to replace some other lesser known UCLA fight songs such as "Sing U.C.L.A.", "By the Old Pacific's Rolling Waters", "Team, Hear our Song", and "Fight on Men of Westwood".
Although the UCLA Band no longer performs "Fight on Men of Westwood", "Team, Hear Our Song", or "Sing UCLA" ("By The Old Pacific" is still heard occasionally, and is featured on the official band CDs), they are a part of the musical repertoire performed by the UCLA Alumni Band as part of their pre-game concert during every home game.