After commissioning and workup, "Hermione" joined the 15th Cruiser Squadron of the Home Fleet. "Hermione" took part in the pursuit of the and heavy cruiser when they sortied into the North Atlantic in May 1941. "Hermione" left Scapa Flow on 22 May as part of a force including the battleship and the aircraft carrier . On 24 May, "Victorious", escorted by "Hermione", and , was detached to launch an air attack against "Bismarck". The attack by "Victorious"s Swordfish torpedo bombers resulted in a single torpedo hit on "Bismarck" which did little damage to the German ship. On 25 May, "Hermione", short of fuel, was detached from the chase in order to refuel at Iceland. Following the sinking of "Bismarck", the British launched a major operation against German supply ships in the Atlantic which supported the operations of surface raiders, with "Hermione" taking part in searches for these supply ships and German blockade runners before joining Force H, based at Gibraltar on 22 June.