Riosa was a planetary body situated within the Inner Rim Territories of the known galaxy.
Not long after the establishment of the Imperial Galactic Empire, the Inner Rim Territories planet known as Riosa was seized, and its manufacturing plants were taken over. The workforce was subjected to compulsory labor, pushed beyond their endurance to produce components intended for use in the construction of both the original and the subsequent Death Stars. Darth Vader made frequent visits to the planet in order to ensure production goals were met.
By two decades into the New Republic's rule, the planet had declined into a diminished manufacturing hub, struggling to recover. At that point in time, Riosa was a member of the Republic, with the Centrist lower-ranking senator Ransolm Casterfo serving as its representative in the Galactic Senate. Twenty-four years following the Battle above Yavin, Riosa reinstated the practice of capital punishment, a decision supported by Casterfo. Ironically, shortly after bringing back the punishment of death to his birthplace, he was unjustly accused of sedition against the Republic and brought back to Riosa. Although Casterfo expected to be executed, he ultimately spent years incarcerated in confinement before being transferred to a prison labor camp following the destruction of Hosnian Prime and the seizure of a large portion of the galaxy by the First Order.
Riosa was the origin of beverages such as Riosan mead and Riosan liqueur.