The ship mounted six 42-calibre BL 15-inch Mk I guns in three twin hydraulically powered gun turrets, 'A', 'B' and 'Y' from front to rear. Her secondary armament consisted of 17 BL 4-inch Mark IX guns, fitted in five triple and two single mounts. "Repulse" mounted a pair of QF 3-inch 20 cwt anti-aircraft guns mounted on the shelter deck abreast the rear funnel. She mounted two submerged tubes for British 21 inch torpedo torpedoes, one on each side forward of 'A' barbette.