Arthur William Oldham (6 September 1926 – 4 May 2003) was an English composer and choirmaster. He founded the Edinburgh Festival Chorus in 1965, the Chorus of the Orchestre de Paris in 1975, and the Concertgebouw Orchestra Chorus in Amsterdam in 1979. He also worked with the Scottish Opera Chorus 1966–74 and directed the London Symphony Chorus 1969–76. For his work with the LSO Chorus, he won three Grammy Awards. He was also a composer, mainly of religious works, but also a ballet and an opera.
Arthur Oldham was born in London in 1926. When he was age 14, his mother committed suicide by gassing herself in an oven, and he was brought up in Wallington, at that time in Surrey. He won a scholarship to the Royal College of Music, where he studied composition under Herbert Howells. He then became Benjamin Britten's only private pupil at Aldeburgh between 1945 and 1951. (He claims that the bar lines on the manuscript of Peter Grimes were his work.) He and Britten came into conflict over their ideas about choral music, but they later worked together in Edinburgh on Britten's Voices for Today, Op. 75, and the War Requiem. Until 1968 the only published vocal score of Britten's The Little Sweep was the piano duet and percussion version prepared by Arthur Oldham.
He was appointed musical director of the Ballet Rambert in 1945, aged only 19. His music first came to public notice in 1946, when his ballet Mr Punch was performed by the Ballet Rambert at Sadler's Wells, and was included in the Rambert's 1947–48 tour of Australia and New Zealand. Several of his own pieces were heard at early Aldeburgh Festivals. He also composed for the Royal Ballet for a time.