William James Finegan (3 April 1917 – 4 June 2008) was an American jazz bandleader, pianist, arranger, and composer. He was an arranger in the Glenn Miller Orchestra in the late 1930s and early 1940s.
Born in Newark, New Jersey, Finegan grew up in a household full of piano players. While growing up in Rumson, New Jersey, he taught orchestration to schoolmate Nelson Riddle, and he studied piano with Elizabeth Connelly, piano and musicianship with flautist/alto saxophonist Rudolph John Winthrop (1883–1959), himself a student of Engelbert Humperdinck. He spent time studying at the Paris Conservatory and had his first professional experience leading his own piano trio. Finegan was offered a job as a staff arranger for Glenn Miller after Tommy Dorsey bought a copy of his "Lonesome Road" and recommended him; he remained with Miller until 1942, and arranged such hits as "Little Brown Jug", "Sunrise Serenade", "Song of the Volga Boatmen", and "Jingle Bells", arranged in collaboration with Glenn Miller. Finegan also arranged music for films in which the band appeared, such as Sun Valley Serenade (1941) and Orchestra Wives (1942). He then worked off and on for Tommy Dorsey from 1942 to 1952, including on the 1947 film The Fabulous Dorseys.
After the demise of Miller's orchestra in 1942, Finegan joined Horace Heidt, writing "some pieces for the band that immediately sent its musical stock skyward."
In 1947-48 Finegan studied with Stefan Wolpe in NYC, and lived in Europe from 1948-1950 where he studied with Darius Milhaud and Valerie Soudere, a pianist and composer who premiered Bartók's 3rd Piano Concerto in Paris. After returning to the United States, in 1952, Finegan and Eddie Sauter (whom Finegan had met in 1939) formed a highly successful ensemble, the Sauter-Finegan Orchestra, which remained active until 1957. His composition "Doodletown Fifers" was one of the Sauter-Finegan Orchestra's best-known originals. Following this Finegan found work in advertising, writing music for commercials. In the 1970s he arranged for the Glenn Miller Orchestra and Mel Lewis's orchestra. He taught jazz at the University of Bridgeport in the 1980s. He wrote arrangements for cornetist Warren Vaché (with the Scottish String Ensemble) in 2004, and the vocal group Chanticleer until his death in 2008.