Upon completion of her refit in January 1915, "Triumph" was transferred to the Dardanelles for service in the Dardanelles Campaign. The ship departed Hong Kong on 12 January and stopped at Suez from 7 February to 12 February before moving on to join the Dardanelles Squadron. "Triumph" took part in the opening attack on the entrance forts on 18 February and 19 February, and joined the predreadnoughts and in using her secondary battery to silence the fort at Sedd el Bahr on 25 February. She, "Albion", and were the first Allied battleships to enter the Turkish Straits during the campaign when they carried out the initial attack on the inner forts on 26 February. She also took part in the attack on Fort Dardanos on 2 March 1915. She and "Swiftsure" were detached from the Dardanelles on 5 March for operations against forts at Smyrna, returning to the Dardanelles on 9 March.