Thomas Cochrane, 6th Earl of Dundonald

Upon the death of his unmarried cousin, William Cochrane, 5th Earl of Dundonald, in 1725, he inherited the earldom of Dundonald.^[1]

In October 1727, Lord Dundonald was married to Catherine Hamilton (d. 1779), the second daughter of Lord Basil Hamilton of Baldoon (sixth son of William Hamilton, Duke of Hamilton and Anne Hamilton, suo jure Duchess of Hamilton) and the former Mary Dunbar (a daughter of David Dunbar the Younger of Baldoon, who was the granddaughter and heiress of Sir David Dunbar, 1st Baronet, of Baldoon).^[1] Together, they were the parents of:

• William Cochrane, 7th Earl of Dundonald (1729–1758), who was killed during the Siege of Louisbourg.^[3]
• Hon. Basil Cochrane (d. 1748), who served in the Royal Navy.^[4]
• Lady Katherine Cochrane (d. 1776), who married William Wood of Nether Gallowhill.^[4]
• Lady Charlotte Cochrane (d. 1740).^[4]

Lord Dundonald died at Paisley Abbey on 28 May 1737,^[1] and was succeeded in his titles by his eldest son, William. His widow died on 13 April 1779. On the death of his unmarried heir in 1758, his line died out and the title was inherited by his son's second cousin, Thomas Cochrane.^[5]