Io is the innermost Galilean moon of Jupiter. By 2158 it had been colonized by man. The Kelland Mining Company notably has its headquarters situated on Io. By 2230, the Weyland-Yutani Corporation was also involved with mining on Io, using convict laborers.
- Io is the setting of the 1981 movie Outland, which has been noted as sharing abundant artistic and stylistic similarities to Alien. Many of the same production crew worked on both films.