Science fantasy is a hybrid genre within speculative fiction that simultaneously draws upon or combines tropes and elements from both science fiction and fantasy. In a conventional science fiction story, the world is presented as being scientifically logical, while a conventional fantasy story contains mostly supernatural and artistic elements that disregard the scientific laws of the real world. The world of science fantasy, however, is laid out to be scientifically logical and often supplied with hard science-like explanations of any supernatural elements.

Speculative fiction is an umbrella genre of fiction that encompasses all the subgenres that depart from realism, or strictly imitating everyday reality, instead presenting fantastical, supernatural, futuristic, or other imaginative realms. This catch-all genre includes, but is not limited to, science fiction, fantasy, horror, slipstream, magical realism, superhero fiction, alternate history, utopia and dystopia, fairy tales, steampunk, cyberpunk, weird fiction, and some apocalyptic and post-apocalyptic fiction. The term has been used for works of literature, film, television, drama, video games, radio, and their hybrids.