Single-sexed species

All-female species

• The Rix (all-female cyborgs in The Risen Empire by Scott Westerfeld)
• all-female species in Violent Stars by Phyllis Gotlieb
• The Sharers on Shora in A Door Into Ocean by Joan M. Slonczewski (all-female species of bioengineered humans)
• Lamia in Final Fantasy (FF XI)
• Gria in Final Fantasy (FF Tactics A 2)
• Gerudo in Legend of Zelda (warrior-thieves primarily all-female)
• the Arume in Blue Drop (anime) - all-female reproduce through cunnilingus and nanotechnology; they produce sperm in their mouths
• the Witches in His Dark Materials trilogy by Philip Pullman
• all-female dryad race in the Belgariad by David Eddings

All-male species

• Sontarans in Doctor Who
• Galka in Final Fantasy (FF XI)
• pucks in the Rob Thurman series
• centaurs in Xena: Warrior Princess

Other single-sexed species

• J'Naii in Star Trek: The Next Generation
• Jem Hadar in Star Trek: Deep Space Nine
• the Draks in Enemy Mine (book and film)
• Mithras in Final Fantasy (FF XI)
• Asari in Mass Effect
• Gethenians in Ursula K. Le Guin's Hainish universe, particularly The Left Hand of Darkness. Note, however, that although the species is all one sex (neuter), they go in and out of kemmer in which they (usually) switch to male or female.
• the Preservers in Elf Quest (comic book series) by Wendy Pini and Richard Pini
• the wraeththu in Storm Constantine's Wraeththu series

See also

• One Gender Race @ TV tropes