William (Bill) Julius Theodore Reinhardt was an American clarinetist, bandleader and the owner of Jazz, Ltd.—the first Jazz club run by a musician in Chicago and one of the longest running Dixieland jazz clubs in the country. He also played tenor saxophone, French horn and sang. Unlike many of the famous jazz musicians that Bill employed in his band, he did not seek fame; he was content with the great success of his nightclub. However, by the 1960s his band did appear on two TV programs.

Jazz, Ltd. was a Dixieland jazz band, nightclub and a record label in Chicago.