"Aliens" (also sometimes called "extraterrestrials") refers to species that are not native to a planet. For example, Kryptonians and Thanagarians are both aliens to the planet Earth.
- Humans: Race of humanoids, identical in appearance to Kryptonians.
- Amazons: Super-powered and militaristic female humans.
- Atlanteans: Super-powered aquatic humans.
- Kryptonians: Race of highly sophisticated humanoids, identical in appearance to humans.
- Thanagarians: Humanoids identical in appearance to humans and Kryptonians, but with large wings.