During the Spanish Civil War of 1936–1939 the ship enforced the arms blockade imposed by Britain and France on both sides as part of the Mediterranean Fleet.

During the first few months of World War II, Hero searched for German commerce raiders in the Atlantic Ocean and took part in the Second Battle of Narvik during the Norwegian Campaign of April–June 1940 before she was transferred to the Mediterranean Fleet in May where she escorted a number of convoys to Malta.

She was damaged by German dive bombers while rescuing survivors from the minelayer Latona in October 1941 and resumed escorting convoys to Malta.

She sank two German submarines whilst stationed in the Mediterranean in 1942, and was transferred back home late in the year to begin converting to an escort destroyer.

She became part of the Mid-Ocean Escort Force in early 1944 until her transfer back to British coastal waters in May to protect the build-up for Operation Overlord.

Hero carried a maximum of 470 long tons (480 t) of fuel oil that gave her a range of 5,530 nautical miles (10,240 km; 6,360 mi) at 15 knots (28 km/h; 17 mph).

For anti-aircraft (AA) defence, Hero had two quadruple Mark I mounts for the 0.5 inch Vickers Mk III machine gun.

[5] Ordered on 13 December 1934 from Parsons Marine Steam Turbine Company, Hero was subcontracted to Vickers-Armstrongs and laid down by their High Walker Yard at Newcastle-on-Tyne, England, on 28 February 1935.

[6] Most ships of Hero's class had the rear torpedo tubes replaced by a 12-pounder AA gun after the evacuation of Dunkirk in 1940, but it is not clear if she underwent this refurbishment as she was deployed in the Mediterranean until 1943.

She sortied into the North Atlantic when Convoy WS-5A reported that it had been attacked by the German cruiser Admiral Hipper on 25 December to round up the scattered ships.

After refueling in Alexandria on 23 April, Hero took part in Operation Demon, evacuating British and Australian troops from Greece.

On 27 April Hero towed the Dutch troop ship Costa Rica, which had been damaged by a German air attack.

[16] Hero escorted the LSI(L) Glengyle as she conducted an amphibious landing in early June 1941 on the Lebanese coast during the opening stages of the Operation Exporter.

[11] Together with her sister Hotspur and the destroyer Encounter, the ship escorted Latona on 25 October whilst en route to Tobruk.

[21] During Operation Vigorous in June, Hero formed part of the escort for the covering force of the Mediterranean Fleet for the Malta-bound convoy.

In conjunction with four other destroyers and a Wellesley light bomber of the Royal Air Force, Hero sank U-559 60 nautical miles (110 km; 69 mi) north-east of Port Said on 30 October.

The ship was ordered back to the United Kingdom, via the Cape of Good Hope, to be converted to an escort destroyer late in the year.

On 6 March 1944, whilst defending Convoy HX 228 west of Ireland, the escorts forced U-744 to the surface where she surrendered after a 32-hour hunt.