The HMS Colossus was a dreadnought battleship in the British Royal Navy and the lead ship of the Colossus class. Designed as a more heavily armored version of the battleship Neptune. The Colossus class was the last class of dreadnoughts in the British fleet before the construction of superdreadnoughts, such as the Orion class with 343 mm artillery. Colossus was laid down on July 8, 1909; launched on April 9, 1910; and commissioned on August 8, 1911. Although the Colossus took part in the Battle of Jutland, its combat career mainly consisted of routine patrols and exercises. By the beginning of World War I, the ship was obsolete and considered second-rate. After WWI ended, the ship was placed in reserve and used for training until 1920. In 1928, the ship was cut up for scrap.

The HMS Colossus was introduced in Update 2.1 "New Power", in its 1918 modification. In the game, the ship is a typical example of the first generation of dreadnoughts. It has mediocre armor by battleship standards and weak anti-aircraft defenses. Its extremely complex main battery layout limits its ability to fire a full broadside salvo to a limited sector.