HMS Renown was the lead ship of her class of battlecruisers of the Royal Navy built during the First World War. She was originally laid down as an improved version of the Revenge-class battleships. Her construction was suspended on the outbreak of war on the grounds she would not be ready in time. Admiral Lord Fisher, upon becoming First Sea Lord, gained approval to restart her construction as a battlecruiser that could be built and enter service quickly. The Director of Naval Construction (DNC), Eustace Tennyson-D'Eyncourt, quickly produced a new design to meet Fisher's requirements and the builders agreed to deliver the ships in 15 months. They did not quite meet that ambitious goal but the ship was delivered a few months after the Battle of Jutland in 1916. Renown, and her sister HMS Repulse, were the world's fastest capital ships upon completion.

The battlecruiser was a type of capital ship of the first half of the 20th century. These were similar in displacement, armament and cost to battleships, but differed in form and balance of attributes. Battlecruisers typically had thinner armour and a somewhat lighter main gun battery than contemporary battleships, installed on a longer hull with much higher engine power in order to attain greater speeds. The first battlecruisers were designed in the United Kingdom, as a development of the armoured cruiser, at the same time as the dreadnought succeeded the pre-dreadnought battleship. The goal of the design was to outrun any ship with similar armament, and chase down any ship with lesser armament; they were intended to hunt down slower, older armoured cruisers and destroy them with heavy gunfire while avoiding combat with the more powerful but slower battleships. However, as more and more battlecruisers were built, they were increasingly used alongside the better-protected battleships.