Trantor is a planet in Isaac Asimov's Foundation universe and Galactic Empire novels. Trantor was first described in a short story by Asimov appearing in Early Asimov Volume 1. Later Trantor gained prominence when the 1940s Foundation Series first appeared in print in the form of short story. Asimov described the planet as being in the centre of the Milky Way. In later stories he acknowledged the growth in astronomical knowledge by retconning its position to be as close to the galactic centre as was compatible with human habitability. The first time it was acknowledged in novel form was in Pebble in the Sky.
Trantor is also an inhabited asteroid in Paul McAuley's novel Evening's Empire.