Cyril John Mockridge was an English film and television composer. He received professional training at the Royal Academy of Music in London. In the early 1930s, Mockridge went to Hollywood where he scored and arranged the music for more than a hundred films including Cheaper by the Dozen, River of No Return and The Man Who Shot Liberty Valance.
He was nominated for an Academy Award for the 1955 film Guys and Dolls with Jay Blackton.
Mockridge spent years as a staff composer for Twentieth Century-Fox, frequently working with Alfred Newman and Alfred's brother Lionel. He retired to Hawaii, where he died in 1979 and is buried at Forest Lawn Memorial Park in Hollywood Hills, Los Angeles.