William H. Challis (Jul 8, 1904, Wilkes-Barre, Pennsylvania - October 4, 1994, Harveys Lake, Pennsylvania) was an American jazz arranger, best known for his association with the Paul Whiteman orchestra.
Challis played piano and saxophone, and was a bandleader at Bucknell University in the early 1920s. He was hired by Jean Goldkette as an arranger in 1926, and moved with Bix Beiderbecke to Paul Whiteman's ensemble in 1927. He wrote scores for Whiteman's full band as well as smaller ensembles drawn from its ranks (such as those led by Frank Trumbauer), and was in part responsible for Beiderbecke's robust representation on Whiteman's Victor Records releases in the late 1920s.
Challis departed from Whiteman's employ in 1930 and did contract arrangements for many major swing era bands, including the Casa Loma Orchestra, Jimmy and Tommy Dorsey, Lennie Hayton, Fletcher Henderson, Artie Shaw, and Frank Trumbauer. He also arranged for radio broadcasts. Later in his career he arranged for popular singers and ensembles.