James Douglas McLachlan CB CMG DSO (1869–1937) was the first British wartime Military attaché to Washington, D.C. James Douglas McLachlan was born in Semarang, Java, 14 February 1869 and commissioned into the Queen's Own Cameron Highlanders in 1891.

He married Gwendolen Mab White,[2] of Havilah, New South Wales in 1903 at St Margaret Church in London.

[3] As lieutenant colonel, McLachlan commanded the 1st Battalion of the Cameron Highlanders in March 1913 and led it to France in the early stages of the World War I until September 1914, when he was wounded.

He served on the staff as a Brigadier General before being appointed as the first wartime military attaché to the United States;[4] he arrived in the United States with his wife and two school girl daughters on 11 September 1917.

Upon relinquishing his post as military attaché, he reverted to his substantive rank of Colonel.