He was the eldest son of John Dalrymple, 12th Earl of Stair and Violet Evelyn Harford.
His maternal grandparents were Col. Frederick Henry Harford and Florence Helen Isabella Parsons (a granddaughter of the 2nd Earl of Rosse).
[3] As a Lieutenant-Colonel of the 1st Battalion, Scots Guards between 1942 and 1943, took part in World War II, fighting in the Middle East and Central Mediterranean.
[4][5] On 14 January 1960, Lord Stair married the Queen's cousin, Davina Katherine Bowes-Lyon (1930–2017), a daughter of the Hon.
Together, they had three children:[2] Lord Stair died at Lochinch Castle on 26 February 1996, aged 89, and was succeeded by his eldest son, John.