In the various incarnations of Star Trek across the decades, there have been some important characters who are half-human, one of their parents being an alien:

  • Mr Spock, from TOS, is half-human and half-Vulcan
  • Deanna Troi, from TNG, is half human and half-Betazoid

Which got me wondering: how many such pairings are possible in the Star Trek universe?

How many alien species are known to be compatible with humans?

For the pedants and nitpickers:

  • "are known to be compatible" means "have produced offspring at least once"
  • this is about reproductive, not sexual, compatibility: if Kirk had sex with an alien, it's not enough to qualify that species unless she bore him a child
  • yes, this is a list question, but it's a finite and clearly scoped one.
  • 7
    If you believe TNG The Chase, then the answer could be: all of them.
    – Xantec
    Apr 21, 2016 at 20:14
  • Almost all of them naturally and pretty much all of them with some medical jiggery-pokery.
    – Valorum
    Apr 21, 2016 at 20:16
  • There is direct evidence of half-Klingon (Worf's mate), and half-Romulan. Not directly to the question, but there were also Klingon-Romulan children. I don't recall if the Q who was raised on Earth was all Q or half-Q.
    – KevinO
    Apr 21, 2016 at 20:19
  • 1
    If you want a list of partial-human hybrid types that appear in canon, maybe the title should ask for that. Like Xantec said, there's a canon suggestion that pretty much any humanoid species should be compatible with humans.
    – Molag Bal
    Apr 21, 2016 at 20:22
  • 2

3 Answers 3


In addition to your examples, on screen there are:

I have omitted several known descendants of the above individuals, as well as less prominent characters who provide examples of hybrids with the same species listed above.

There are several other borderline examples: melding of species which did not imply biological reproduction, and so forth. For a more exhaustive list of inter-species hybrids, consult the Memory Alpha Hybrid page, which I consulted heavily for this answer.

  • Saavik from Star Trek II was half Vulcan, half Romulan, according the the script. Apr 21, 2016 at 20:53
  • In TNG Angel One humans are compatible with the natives of Angel One. However, I don't believe their species is ever mentioned and they look very human, so the 'Angel One'-ians could be human.
    – Xantec
    Apr 21, 2016 at 21:29
  • 2
    @Xantec Yeah, that's why I excluded them with the edge cases. Also, IIRC, the descendants are not shown.
    – Politank-Z
    Apr 21, 2016 at 21:32
  • 1
    Worf had a child, Alexandre, with a woman who was half Klingon and half human.
    – user48960
    Apr 26, 2016 at 4:49

Another example is the pilot of the starship from the future in ENT 'Future Tense'. Phlox identifies that the pilot was human, but also had Vulcan and Terrelian DNA, showing that humans are probably also compatible with Terrelians.

  1. Cardassians and Bajorans
  2. Kazon and Cardassians
  3. Seska believed it was possible for a human and Cardassian to have a child.
  • It appears to me that the OP is asking about species that are compatible with humans, but your items 1 and 2 are compatible within themselves, if I understand correctly. Can you provide information for number 3? Mar 6, 2017 at 5:24

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