Bellassa existed as a world within the bounds of the Core Worlds. Its location was identified as grid square M-11 on the Standard Galactic Grid. The Hydian Way super-hyperroute provided a connection for Bellassa to the planets Exodeen and Fedalle. The name Bellassa was also used to refer to the Bellassan pepper, as well as the Bellassan Galaxy Petitionists rebel faction.
Sometime around 9 ABY, the crew of the Onyx Cinder starship journeyed to the Observatory Moon in order to seek the help of astronomer Kh'ymm in locating the lost world of At Attin. While Kh'ymm was searching through her records for any potential locations of At Attin, Bellassa appeared on her computer's display, written in the Aurebesh script, among other possible locations. In 34 ABY, the Star Cruiser Halcyon of Chandrila Star Line traveled near Bellassa during a cruise that went from the Chandrila system in the Core Worlds to the Outer Rim Territories. Several screens inside the starship showed a partial map of the galaxy that highlighted the position of Bellassa.
Within the current Star Wars canon, the initial mention of Bellassa was in the fifty-second issue of the magazine Star Wars: Build the Millennium Falcon, released by De Agostini around December 30 of 2015. Bellassa's first in-universe appearance was its depiction on a map that could be seen in Star Wars: Galactic Starcruiser, an interactive role-playing experience located at Walt Disney World Resort in Florida, which became accessible to the public on March 1 of 2022.
Within the Star Wars Legends continuity, the planet Bellassa originally appeared in the young reader novel The Last of the Jedi: The Desperate Mission from 2005, which was penned by Jude Watson and was the first book in the Star Wars: The Last of the Jedi series. Its first visual depiction occurred in Pablo Hidalgo's reference book The Essential Reader's Companion, released in 2012.