Planet X (disambiguation)

Planet X may refer to:

In-universe

 * Planet X (Famine on Planet X) - The planet featured in the Doctor Who annual short story Famine on Planet X
 * Planet X (Risk Assessment) - A planet mentioned in the Torchwood novel Risk Assessment
 * Planet X (Planet X) - The planet featured in the Bernice Summerfield audio story Planet X

Real world

 * Planet X - the second story in The New Adventures of Bernice Summerfield Volume 3: The Unbound Universe