The band confirmed his death in a brief statement, saying members were saddened to announce the passing of their founder. They added it had been a privilege to work with him for 50 years.
International outlets, including Rolling Stone, reported that Davies died on Saturday at his home in Long Island, New York, after a long illness.
While no official cause of death has been released, Davies had been battling leukemia for more than a decade.
Born in 1944, Davies co-founded Supertramp in 1969 with Roger Hodgson. The band rose to international fame with hits such as The Logical Song, Breakfast in America, and Dreamer.
