An Outer Rim planet in a system of the same name, Xo was located in the Spinward sector and possessed a breathable atmosphere and red-colored sky. The planet's surface featured rocky, mountainous terrain, and thick jungle, home to spiked, carnivorous plants, and reptilian creatures.
Prior to its collapse in 25,200 BBY, Xo was a remote holding of the Rakatan Infinite Empire. The Sith pureblood Kyyrah, a warrior who was held captive by the Rakata in the Eternity Vault on Belsavis, was known as the "Jewel of Xo." Pre-Republic era Humans constructed an elevated temple in the planet's jungle. The site of a great battle, the temple remained unconquered, but was abandoned, and had fallen to ruin by the New Republic era.
In 11 ABY, New Republic operative Mirith Sinn and her traitorous former subordinate Massimo were brought to Xo as captives of the Zanibar. Sinn was rescued from a Zanibar village's sacrificial ceremony by renegade Imperial Guard Kir Kanos.
The planet Xo was first mentioned in the January 1999 Dark Horse Comics issue Crimson Empire II: Council of Blood 3, and made its first appearance in the following issue released in February of that year, both of which were written by Mike Richardson and Randy Stradley and illustrated by Paul Gulacy.
- Star Wars Handbook 2: Crimson Empire
- The Complete Star Wars Encyclopedia
- The Essential Atlas
- The Bounty Hunter Code: From the Files of Boba Fett