Irving Harold Mills (1894–1985), who had worked for the publisher Leo Feist founded Jack Mills Music in 1919 with his brother Jack who had worked at another publisher, McCarthy and Fisher. It was renamed Mills Music Inc. in 1928.
The Mills brothers engaged many famous songwriters, including Zez Confrey, Sammy Fain, Harry Barris, Gene Austin, Hoagy Carmichael, Jimmy McHugh, and Dorothy Fields.
Mills was active in sound recording, movies and artist management. In 1934 Mills started, Exclusive Publications, Inc., specializing in orchestrations by Will Hudson (1908–1981) and others.
Mills Music Publishers merged with Belwin, Inc., founded in 1918 by Max Winkler, to form the Belwin-Mills Publishing Corporation in 1969, with Martin Winkler as director. It is now based in Miami and specialises in educational music. The imprint is part of Alfred music's list.