The HMS Queen Mary was a battlecruiser of the Royal Navy, the last battlecruiser built before World War I. The ship was named after Queen Mary, wife of King George V. It was laid down at the Palmers shipyard on March 6, 1911, launched on March 20, 1912, completed in August 1913, and commissioned on September 4. Originally planned as the third of the Lion class, the abundance of changes made to the design allowed it to be classified as a separate type. These changes included improvements to the armor plating of the decks in the forecastle area and protection for the bow battery against shells of mine caliber, as well as an increase in the size of the hull and the power of the engines.

At the start of World War I, the cruiser was part of the First Squadron of battlecruisers in the Grand Fleet. It participated in the Battle of Heligoland Bight, but did not distinguish itself. It subsequently took part in the pursuit of German battlecruisers during the raid on Hartlepool, Scarborough, and Whitby; however, the Germans managed to evade engagement. In early 1915, the ship underwent repairs in Portsmouth, causing her to miss the Battle of Dogger Bank. On May 31, 1916, the cruiser took part in the Battle of Jutland, scoring several hits on the German battlecruiser SMS Seydlitz and causing serious damage. At 16:26, however, the Queen Mary exploded and sank, presumably from concentrated return fire from the Seydlitz and the Derfflinger. The explosion took the lives of 1,266 crew members.

The HMS Queen Mary was introduced in Update 2.37 "Seek & Destroy" and is depicted in its 1915 modernization. It is a typical World War I battlecruiser with weak armor and a complete lack of anti-aircraft defense. However, it has very good speed and maneuverability for a capital ship, as well as powerful main-caliber guns.