Downbelow (also known as Pell's World) is a fictional planet in American science fiction and fantasy author C. J. Cherryh's Alliance-Union universe. It is the first planet discovered by humans with an advanced ecosystem and, even more significantly, intelligent alien life in the form of the Hisa. Pell Station, a star station prominent in this universe, orbits the planet. Downbelow features in a number of Alliance-Union universe novels, in particular Downbelow Station and Finity's End.