Thomas Hesketh Douglas Blair Cochrane, 13th Earl of Dundonald (21 February, 1886 – 23 May, 1958) was a British Army officer who served in World War I.

[3] He succeeded to the Earldom of Dundonald and its subsidiary titles of 13th Lord Cochrane of Paseley and Ochiltrie on the death of his father, 12 April 1935.

He lived a secluded life in his later years at his home in Auchans Castle, Ayrshire where he very rarely partook in public affairs.

He entered the Scots Guard in 1908 and reached the rank of captain, he fought in France in World War I and he was also a General Staff for the Egyptian Expeditionary Force.

In 1919, Cochrane's mother sold portions of the family estate, including surrounding land and mines.