The Magazine of Fantasy & Science Fiction is a U.S. fantasy and science fiction magazine, first published in 1949 by Mystery House, a subsidiary of Lawrence Spivak's Mercury Press. Editors Anthony Boucher and J. Francis McComas had approached Spivak in the mid-1940s about creating a fantasy companion to Spivak's existing mystery title, Ellery Queen's Mystery Magazine. The first issue was titled The Magazine of Fantasy, but the decision was quickly made to include science fiction as well as fantasy, and the title was changed correspondingly with the second issue. F&SF was quite different in presentation from the existing science fiction magazines of the day, most of which were in pulp format: it had no interior illustrations, no letter column, and text in a single-column format, which in the opinion of science fiction historian Mike Ashley "set F&SF apart, giving it the air and authority of a superior magazine".

A science fiction magazine is a publication that offers primarily science fiction, either in a hard-copy periodical format or on the Internet. Science fiction magazines traditionally featured speculative fiction in short story, novelette, novella or novel form, a format that continues into the present day. Many also contain editorials, book reviews or articles, and some also include stories in the fantasy and horror genres.