Arnold Ross (January 29, 1921, Boston - June 5, 2000, Culver City, California) was an American jazz pianist.
Arnold learned clarinet, trumpet, and violin as a child before picking up piano when he was twelve years old. He played on a cruise ship before relocating to New York City, working there with Jack Jenney. He then joined Vaughn Monroe's backing band, and in 1943 was drafted and entered the Glenn Miller Army Air Force Band. From 1944 to 1947 he worked with Harry James; around the same time he played with Harry Edison, Charlie Ventura, and Charlie Parker. He moved to California in 1947, working with Lena Horne, Dizzy Gillespie, Bob Crosby, and Billy Eckstine, in addition to leading his own small group.
By 1960 Ross had become addicted to heroin, and entered a Synanon treatment program; he became affiliated with the Synanon organization and appeared in the Synanon film in 1965. He worked extensively with Nelson Riddle from 1968 to 1976, and was active as a touring performer into the 1990s.