Modern science fiction frequently involves themes of sex, gender and sexuality. This was not always so. During the 1930s and 40s "golden age" of science fiction it was unusual to find males and females mentioned in the same paragraph, let alone having sex.
In spite of this, book covers for pulp science fiction often featured scantily clad women, often with guns or being menaced by aliens. In some ways, little has changed: many science fiction book covers still feature images of sexy women by artists such as Boris Vallejo and Frank Frazetta, although the images are perhaps somewhat less exploitative than before.
The New Wave science fiction of the 1960s and 1970s reflected its times by attempting to break earlier taboos about what could and could not be the subject of science fiction. The men's magazine Playboy published regular serious science fiction stories throughout this period, by both male and female authors, offering them significantly more scope than some other publications.
Two different themes emerged: one trying to explore the boundaries of what "sex" could mean in a world of altered humanity and reality, and another of exploring the position of women in science fiction and feminist issues in what had been traditionally a form of fiction written primarily by and for men.
Significant uses of sexual themes in serious science fiction include:
- Brave New World by Aldous Huxley
- Several stories in Dangerous Visions, edited by Harlan Ellison
- A number of works by Philip Jose Farmer: The Lovers, Flesh, his collection of stories on this theme, Strange Relations, plus two science fiction pornographic novels, Image of the Beast and Blown.
- The Left Hand of Darkness by Ursula K. Le Guin
- Dhalgren and several other works by Samuel Delany
- Tower of Glass by Robert Silverberg
- Titan and other novels by John Varley, set in a future where sex changes and other body modifications are commonplace
- The Handmaid's Tale by Margaret Atwood
- The Female Man by Joanna Russ
- The Culture novels of Iain M. Banks, where humans can change sex at will
- The Jerry Cornelius stories of Michael Moorcock and others
- The Moon is a Harsh Mistress by Robert A. Heinlein (various forms of group marriage, professional host-mothers)
- Ethan of Athos by Lois McMaster Bujold
- The Gods Themselves by Isaac Asimov
- Strangers by Gardner Dozois
- The Dune series of novels by Frank Herbert
- A number of works by Theodore Sturgeon, including The World Well Lost (alien homosexuality) and Godbody (religious sexuality).
- The Primal Urge by Brian Aldiss
- VESTA - Painworld by Jennifer Jane Pope
- The Tales of the Velvet Comet trilogy by Mike Resnick
- Several books by Spider Robinson, including Callahan's Lady
- Jurgen by James Branch Cabell
- The Bachelor Machine by M. Christian
- Trouble on Triton by Samuel Delany
- Sex with aliens, machines and robots
- Reproductive technology including cloning, artificial wombs and genetic engineering
- Sexual equality of men and women
- Male- and female-dominated societies, including single-sex societies
- Changing sex roles
- Homosexuality and lesbianism
- Androgyny and sex changes
- Sex in virtual reality
- Sexual bonding and politics
- Sex in zero gravity
In recent years there has been a growing BDSM awareness in the science fiction and fan community.
Numerous science fiction television series and science fiction films have used science fiction plots as an excuse to fit in gratuitous sexual or fetishistic content: one of the conventions of much filmed science fiction appears to be that the future will be peopled exclusively by attractive people wearing skin-tight clothing in shiny materials. Nevertheless, some science fiction-themed TV shows, such as Farscape, have been acclaimed for their handling of such themes. The series Lexx features sexual themes in almost every episode.