On 5 August 1914, the squadron had eight ships:,,,,,, and Zealandia. The squadron of eight King Edward VII-class pre-dreadnought battleships were nicknamed "the wobbly eight" after their slight tendency to roll under way. The squadron was initially used as part of the Grand Fleet in support of the cruisers on the Northern Patrol. On 29 April 1916, the 3rd Battle Squadron was moved to Sheerness from Rosyth and came under the Nore Command in the Thames estuary. The move was intended to make more large ships available for coastal defence duties, after the Bombardment of Yarmouth and Lowestoft by German ships on 24 April 1916. At the time of the Battle of Jutland, the squadron consisted of: , Africa, Commonwealth, Hibernia, Dominion, Hindustan, Zealandia and Britannia, plus the repeating cruiser. In addition the 3rd Cruiser Squadron, consisting of the armoured cruisers, and, was attached, together with the destroyers ,,,, and from the 1st Destroyer Flotilla, and and from the 10th Destroyer Flotilla. Essentially made obsolete by the introduction of the revolutionary battleship, and as battleships the world over began mimicking her design, the 3rd Battle Squadron played no role in the Battle of Jutland. The need for accompanying destroyers for these battleships was later given as the reason the Harwich destroyer squadron was also held back and took no part in the Jutland action. Following the loss of King Edward VII in January 1916, Africa and Britannia served in the Mediterranean 1916–17. The remaining ships were augmented by Dreadnought until March 1918. The squadron was disbanded on 20 April 1918.
Later in the war, the squadron was based at Halifax, Nova Scotia. Rear Admiral, Third Battle Squadron, was responsible for covering Atlantic convoys; and was later to become the North Atlantic Escort Force. At the time, German surface raiders were a distinct concern, thus the allocation of battleships. RMS Ascania—an armed merchant cruiser—was part of the squadron during this period. Seaborn—a Fleet Air Arm base was established at RCAF Station Dartmouth in September 1940. Seaborn was to provide a shore base with administrative and maintenance facilities for the Swordfish and Walrus aircraft assigned to ships of the Third Battle Squadron. In 1942, the Third Battle Squadron, now comprising;
sailed for the Far East and became part of the Eastern Fleet. The squadron formed part of Force B. Facing the superior striking force of the Japanese Kido Butai carrier striking force during the 1942 Indian Ocean raid, the slow component of the Eastern Fleet—including the battleships of Force B—was withdrawn all the way back to Kilindini in East Africa to avoid their destruction at Japanese hands. Hermes—Force B's sole aircraft carrier—was detached and destroyed near Ceylon. In 1945, the Squadron consisted of two battleships, and the Free French, as well another two escort carriers, four cruisers and six destroyers. Two battleships and escort carriers formed part of the covering force for Operation Dracula, the retaking of Rangoon. Vice-Admiral H.T.C. Walker commanded the squadron at the time.
