[1] Hector was born in a tent on the hill of Sheikh Budin, in the Northwestern Provinces of India, now Pakistan.

On 17 August 1897 at Nawa Kili, Upper Swat, British India, Lieutenant Maclean, with fellow officers Robert Bellew Adams and Alexander Edward Murray, Viscount Fincastle and five men of the Guides, went under a heavy and close fire, to the rescue of a Lieutenant Greaves of the Lancashire Fusiliers who was lying disabled by a bullet wound and surrounded by enemy swordsmen.

His citation read: During the fighting at Nawa Bali, in Upper Swat, on the 17th August, 1897, Lieutenant-Colonel R. B. Adams proceeded with Lieutenants H. L. S. MacLean and Viscount Fincastle, and five men of the Guides, under a very heavy and close fire, to the rescue of Lieutenant R. T. Greaves, Lancashire Fusiliers, who was lying disabled by a bullet wound and surrounded by the enemy's swordsmen.

His nephew, Vice Admiral Sir Hector Charles Donald Maclean, was the maternal grandfather of actor Rupert Everett.

His VC is on display in the Lord Ashcroft Gallery at the Imperial War Museum, London.