Magazine Publishers was a pulp magazine publishing house established by Harold Hersey and later owned by A. A. Wyn in 1929. Under Wyn, it was known as "Ace Magazines", hence titles such as Ace Mystery and Ace Sports. They also used the name "Periodical House", and also branched out to publishing comic books as Ace Comics. In the 1940s the company also began publishing books.
In 1952 Wyn founded Ace Books, and by the mid-fifties Wyn had sold most or all of his hardback rights, and may also have ceased publishing magazines by that time to focus on Ace Books.