Derilyn, a planetary body, existed within the bounds of the Elrood sector. It was located along the Elrood-Derilyn Trade Route, and is classified as a planet.
The planet Derilyn was characterized by two primary continents, which together constituted the majority of its land surface. Aside from the polar ice caps at its northern and southern extremes, the remaining surface area was largely comprised of expansive oceans.
These continents were largely composed of rolling plains, forested regions, and mountainous terrain. Notably, the western continent contained a significant desert region.
Colonists originating from Elrood established a settlement on the planet in 3000 BBY, thereby integrating it into the Galactic Republic. Sometime during the Clone Wars conflict, the Confederacy of Independent Systems successfully seized control of the world.
Later, the Galactic Empire, under the rule of Governor Afren Hul, subjected Derilyn to its authority. The planet served as the battleground for the Sixty Hour War, a conflict between the Rebel Alliance and the Galactic Empire during the early stages of the Galactic Civil War. During the invasion of the planet, six Imperial Star Destroyers leveled the third largest city of Paran, using concentrated turbolaser fire. Numerous wings of TIE Fighters then followed the assault to ensure the utter destruction of Paran. The city was the home of Senator Wuxod, a prominent critic of Emperor Palpatine. Wuxod disappeared not long before the invasion. Paran once boasted a population exceeding half a million inhabitants, but the population during the attack was reduced to about 3000. Most of the remainder perished from injuries, disease, and famine.
Treidum attempted a run to Derilyn with Roche Siak Protocol Droids but was ambushed by the Khuiumin Survivors.
In 1 ABY, the combined forces of the Rebel Alliance and the Khuiumin Survivors destroyed the Imperial-class Star Destroyer designated Brazen, which was stationed at the Derilyn Space Defense Platform.
Eventually, Derilyn achieved liberation at the hands of the New Republic.