Species with three or more sexes
This includes human species (in future or alternate incarnations), humanoid species, and non-humanoid species. Includes species with more than two genders, as well as species which are defined as hermaphroditic; does not include single-sex species in which one of the currently existing human sexes continues to exist, such as parthenogenetically-reproducing all-female species.
Future or mutated humans
- Future humans in Proud Man by Katharine Burdekin.(1934; 1993) A human from the future visits 1930s England; humans in the future have evolved "beyond" humanity, and beyond humanity's bi-sexed nature; each individual can reproduce on their own, and is whole, containing both male and female attributes. This human contemplates with amazement the various social oddities of modern English society.
- The Wraeththu, future humans; by Storm Constantine
- Future humans in Shadow Man by Melissa Scott. (1995) space travel creates five common genders
- The future human Gethenians in Ursula K. Le Guin's The Left Hand of Darkness: Neuter most of the time, but male and female in potential; when they go into kemmer, a type of genderizing heat, they go into one or the other gender.
- Isaac Asimov. Foundation and Earth (1986) [a hermaphroditic variety of humans; one joins the protagonists]
Alien humanoids
- A hermaphroditic female-ish humanoid species in Stranded by Camarin Grae. Stranded (1991, Naiad) (3 women from a hermaphroditic species are sent as "disembodied minds" to Earth to stop a villain. They end up identifying as lesbians and fighting a fundamentalist movement led by the villain.)
- The three-way species, including human species, in Dark Water's Embrace (1998) and Speaking Stones (1999) by Stephen Leigh. Includes male, female, and "midmale".
Non-humanoids
- Chocky, an alien non-gendered species
- William Tenn's short story "The Seven Sexes," featuring an alien race in which all seven sexes must participate to mate.
Others
- Duchamp, L. Timmel. "Motherhood, Etc." (1993)
- Joyce, Graham, and Peter F. Hamilton. "Eat Reecebread" (1994)