LGBT themes in speculative fiction refer to the incorporation of lesbian, gay, bisexual, or transgender (LGBT) themes into science fiction, fantasy, horror fiction and related genres. Such elements may include an LGBT character as the protagonist or a major character, or explorations of sexuality or gender that deviate from the hetero-normative.
Science fiction and fantasy have traditionally been puritanical genres aimed at a male readership, and can be more restricted than non-genre literature by their conventions of characterisation and the effect that these conventions have on depictions of sexuality and gender. However, speculative fiction also gives authors and readers the freedom to imagine societies that are different from real-life cultures. This freedom makes speculative fiction a useful means of examining sexual bias, by forcing the reader to reconsider his or her heteronormative cultural assumptions. It has also been claimed by critics such as Nicola Griffith that LGBT readers identify strongly with the mutants, aliens, and other outsider characters found in speculative fiction.
Before the 1960s, explicit sexuality of any kind was rare in speculative fiction, as the editors who controlled what was published attempted to protect their perceived key market of adolescent male readers. As the readership broadened, it became possible to include characters who were undisguised homosexuals, though these tended to be villains, and lesbians remained almost entirely unrepresented. In the 1960s, science fiction and fantasy began to reflect the changes prompted by the civil rights movement and the emergence of a counterculture. New wave and feminist science fiction authors realised cultures in which homosexuality, bisexuality and a variety of gender models were the norm, and in which sympathetic depictions of alternative sexuality were commonplace.