Colonel Sir Donald Walter Cameron of Lochiel, KT, CMG, JP, DL (4 November 1876 – 11 October 1951) was a British Army officer of the Queen's Own Cameron Highlanders, who served in the Second Boer War and the First World War, and the 25th Lochiel of Clan Cameron.

Lochiel began his career as an officer during the Second Boer War. In 1914, Field Marshal Herbert Kitchener, 1st Earl Kitchener requested that he raise several battalions of the Queen's Own Cameron Highlanders. Lochiel served as Colonel of the regiment from 1914 to 1916. The casualties his battalions sustained during the war was said to have deeply affected him. After the war, he retired to his estates in Lochaber with interests in sheep farming and land management, and also advocated for the Scottish Gaelic language revival in Scotland.

Lochiel was born at Dalkeith Palace on 4 November 1876, the eldest son of Donald Cameron, 24th Lochiel and Lady Margaret Montagu Douglas Scott, the daughter of Walter Montagu Douglas Scott, 5th Duke of Buccleuch.^[1] He had three brothers: Ewen, Allan and Archibald; two of whom would be killed during the First World War.^[1] He was educated at Harrow and attended Royal Military Academy Sandhurst.^[2]

Cameron was commissioned in the Grenadier Guards on 5 September 1896, and promoted to lieutenant on 8 September 1898. He served in South Africa 1899-1900 during the Second Boer War, where he was part of the Kimberley relief force, and was wounded at the Battle of Belmont (November 1899).^[3] He was in South Africa for the end of the war, and was invalided home in July 1902, when he left Cape Town on the SS Canada, returning to Southampton.^[4] Lochiel was back with his regiment the same month and promoted to Captain.^[5]

In 1914, Lochiel (who was then commanding officer of the 3rd Reserve Battalion of the Queen's Own Cameron Highlanders) was asked by Field Marshal Herbert Kitchener, 1st Earl Kitchener to raise several battalions of infantry; Lochiel agreed, on condition that he would be Colonel; one of these became the 5th Service Battalion of the regiment, which saw distinguished service on the western front as part 9th (Scottish) Division. His brothers, Allan Cameron and Archibald Cameron, also served in the Cameron Highlanders, but were both killed in 1914 and 1917.^[6][7] Their deaths and those of the many others serving under his command deeply saddened Lochiel.^[1] He was invalided home, but resumed command of the 3rd Battalion in January 1918, when it was in Ireland.^[8]

From 1920 to 1936, he was aide-de-camp to King George V.^[9] He was invested as a Knight of the Order of the Thistle (KT) in 1934, being the first non-peer, or baronet, to receive that honour.^[10] He held the office of Lord Lieutenant of Inverness from 1939 until his death in 1951.^[11] On 1 February 1941, Lochiel was appointed Commander, Inverness Group of the Home Guard.^[12]

Lochiel travelled to America and Canada several times, firstly with his wife in 1913, and again in 1923, returning in 1924. He was also a passionate advocate of the Scottish Gaelic revival; and at various times served as Chief, Gaelic society of Inverness, although he could not speak the language himself.^[13] He was also the first Cameron Chief to organise Clan Cameron gatherings, which took place for the first time in 1938.^[13]

During the Second World War, he vacated his residence of Achnacarry to the military for 25,000 soldiers to undergo elite commando training between 1942 and 1945. Achnacarry, transformed into the Commando Basic Training Centre, was known to the soldiers as "Castle Commando".^[14]

On 29 March 1906, Lochiel married Lady Hermione Emily Graham (1882–1978), the second daughter of Douglas Graham, 5th Duke of Montrose and Violet Graham, Duchess of Montrose, the daughter of Sir Frederick Graham, 3rd Baronet and Lady Jane St Maur, daughter of Edward St Maur, 12th Duke of Somerset.^[15] They had the following issue:

• Violet Hermione Cameron (6 May 1907 – 24 March 1979), married the historian John Stewart of Ardvorlich, and had issue.^[16]
• Col. Sir Donald Hamish Cameron of Lochiel, KT (12 September 1910 – 4 May 2004), who succeeded; married Margot Gathorne-Hardy, a scion of the Earls of Cranbrook, and had issue.^[17]
• Marion Hester Cameron (12 October 1914 – 31 May 1997), married Sir Ronald Orr-Ewing, 5th Baronet, and had issue.^[16]
• Maj. Allan John Cameron (25 March 1917 – 4 December 2011), married Elizabeth Vaughan-Lee; father of Lord Cameron of Dillington and Bride Cameron, who married a cousin, Lord Donald Graham, son of the 7th Duke of Montrose, and had issue.^[17][18]
• Lt.-Col. Charles Alexander Cameron (born 29 September 1920), married Felicia Macdonald, of Tote, Isle of Skye, and had issue.^[17]

Lochiel was recognised by the Lord Lyon King of Arms, and matriculated his arms at the Court of the Lord Lyon in 1934.^[17] As a Knight of the Thistle his arms are encircled by that insignia: