For the magazine of the same name see Science Fantasy (magazine)

Science fantasy is the merging of science fiction and fantasy, two popular genres of writing. The two are notoriously difficult to define, and possibly even more difficult to distinguish. One might claim that science fiction provides a scientific explanation for all phenomena, whereas fantasy mostly takes the supernatural for granted. However, the "science" behind these explanations is often no more than mumbo-jumbo, especially in the pulp magazines. Arthur C. Clarke claims that "any sufficiently advanced technology is indistinguishable from magic," and this is especially true for science fantasy. Hence, it might be said that the difference is more one of stage props: on the one hand we have spacecraft and phasers, on the other hand magic carpets and wands of smiting.

Some excellent science fantasy stories were published in the pulps, such as Robert A. Heinlein's "Magic, Inc.", L. Ron Hubbard's Slaves of Sleep. Fletcher Pratt and L. Sprague DeCamp produced the Harold Shea series. All were relatively rationalistic stories published in John W. Campbell, Jr.'s Unknown Magazine. Henry Kuttner and C. L. Moore published novels in Startling Stories, alone and together, which were also very good and far more romantic. The Magazine of Fantasy and Science Fiction published, among other things, all but the last of the Operation series, by Poul Anderson. These stories, starting in the mid-fifties chronicled the middle-class life of a werewolf named Steve Matuchek married to a witch named Virginia.

The Martian stories of Leigh Brackett might be regarded as science fantasy, as well as M. John Harrison's Viriconium novels, or Gene Wolfe's Book of the New Sun. Many works by Edgar Rice Burroughs, especially his Barsoom novels, clearly fall into this category. Terry Brooks' world depicted in "The Sword of Shannara" sits on this line as well. Perhaps the most well-known example of science fantasy is Star Wars.