The ship was assigned to convoy escort duties in June with the Western Approaches Command, sinking one German submarine in October.

Highlander was transferred to Freetown, Sierra Leone, in mid-1941 to escort convoys off West Africa, but returned to the United Kingdom in August.

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

[4][5] Highlander was completed without a director-control tower (DCT) so the three remaining 4.7-inch low-angle guns fired in local control using ranges provided by a rangefinder.

[6] Little data on Highlander's modifications during the war has survived, although it is known that she had her rear torpedo tubes replaced by a 12-pounder AA gun in July 1940.

A Type 286 short-range surface search radar was fitted as well as a HF/DF radio direction finder mounted on a pole mainmast.

[8] After working up at Portland Harbour, she was assigned to the 9th Destroyer Flotilla of the Home Fleet and began escort duty on 11 April.

During this time, she was briefly refitted in mid-July with a 12-pounder AA gun, replacing her rear set of torpedo tubes and, together with her sister Harvester, the ship sank the German submarine U-32 on 30 October.

[7] After its completion, the ship was briefly assigned to Force H at Gibraltar,[12] before continuing on to Freetown to begin escort duties with the 18th Destroyer Flotilla there.

Highlander crushed her bow on 15 April 1945 when she struck some ice; she had to be towed to Bay Bulls, Newfoundland, for temporary repairs.