Af'El was the homeworld to the Defel, who dwelt in underground cities. It was a high-gravity planet with no ozone layer, and it orbited the ultraviolet supergiant Ka'Dedus. Because of the lack of ozone, ultraviolet light passed freely to the surface, while other light wavelengths were blocked by the heavy gases in the planet's atmosphere. Thus, all animals on Af'El could only see in ultraviolet light ranges. A main export of the planet was the metal meleenium used in durasteel.
Due to the tremendous velocity necessary for a starship to escape Af'El's gravity well, the planet was rarely visited. It was the only known source of naturally occurring meleenium, and as a result, Vulca Minerals made annual trips to the world. A number of private metallurgists and scientists also visited the world to conduct research.
- Star Wars: Knights of the Old Republic II: The Sith Lords (Mentioned only)
- Star Wars 3: Prelude to Rebellion, Part 3 (Mentioned only)
- "Murder in Slushtime"—Star Wars Adventure Journal 14 (Mentioned only)
- Planet of Twilight (Mentioned only)
- Galaxy Guide 4: Alien Races (First mentioned)
- Dark Force Rising Sourcebook
- Wanted by Cracken
- Galaxy Guide 6: Tramp Freighters
- Galaxy Guide 4: Alien Races, Second Edition
- Cracken's Rebel Operatives
- Galladinium's Fantastic Technology (As "Defel")
- The DarkStryder Campaign
- "Wanted by Cracken"—Star Wars Adventure Journal 10
- The Thrawn Trilogy Sourcebook
- Secrets of the Sisar Run
- Star Wars Encyclopedia
- Coruscant and the Core Worlds
- Ultimate Alien Anthology
- Alien Anthology Addendum"—Star Wars Gamer 7 "
- Knights of the Old Republic II: The Sith Lords: Prima Official Game Guide
- The Complete Star Wars Encyclopedia
- Galaxy of Intrigue