HNoMS Uller was a Vale-class Rendel gunboat constructed for the Royal Norwegian Navy at Karljohansverns Verft Naval Yard in Horten in 1874-1876 and had yard build number 55. She was one of a class of five gunboats - the other ships in the class were Vale, Brage, Nor and Vidar.
Uller was, in addition to the heavy, muzzle-loading main gun, armed with a small Quick Fire gun and an early automatic gun, similar to the Gatling gun.
Later Uller and her sister ships were rebuilt as minelayers, and she served in this role when the Germans invaded 9 April 1940.