Oz was a science fiction fanzine by Beryl Mercer (1924-2003).
The first issue of Oz was published in March 1965 in the UK, and distributed through OMPA, Offtrails Magazine Publishers Association. It was the successor to Beryl's previous zine Link. Twelve issues of this title appeared, the last in September 1969.
Letters came from John James and Christopher Priest, among others.
Peter Roberts, In his review in the July 1969 issue of Checkpoint, Peter Roberts says, "Oz (and Beryl thought of the title first) is probably the best fanzine to appear regularly in OMPA, combining, as it does, personal natterings and opinions, mailing comments (though not in this issue), and a couple of guest columns interspersed with the odd article...Recommended."
Beryl Mercer also was co-editor of The Damned Patrol, with Joe Gibson (G2), John Berry (Pot Pourri) and Terry Jeeves (ERG) during the same period Oz was published. After this fanzine, Beryl began co-editing The Middle Earthworm with Archie Mercer.