Space colonization is the establishment of self-sufficient human settlements outside Earth. Interstellar colonization is the establishment of settlements outside of the solar system.

The feasibility of interstellar colonization has substantial implications for the long-term future.

If feasible, this would raise the upper bound on the number of people who could eventually live by many orders of magnitude. On the other hand, given the Fermi paradox, its feasibility could be taken as evidence that humans are likely to go prematurely extinct.

Many difficulties would need to be surmounted before humans, or any other intelligent species, could begin to colonize other star systems. For instance, there would be huge energy requirements, the ability to manage extremely long (possibly intergenerational) flight lengths, and many distinct engineering challenges, such as safeguarding against high-velocity collisions with space dust.

Although there is not yet a substantial body of literature addressing the question, the few scientists who have examined interstellar colonization appear to be optimistic about its long-term feasibility.