John Cochrane, 4th Earl of Dundonald (4 July 1687 – 5 June 1720), was a Scottish aristocrat and politician.
He was the second son of John Cochrane, 2nd Earl of Dundonald and Lady Susan Hamilton.
His elder brother was William Cochrane, 3rd Earl of Dundonald, who did not marry.
[2] On 4 April 1706, Lord Dundonald was married to Lady Anne Murray (1687–1710) at Cramond.
Mary, the widow of Henry Somerset, 2nd Duke of Beaufort, was the youngest daughter of Peregrine Osborne, 2nd Duke of Leeds and the former Bridget Hyde (only daughter and heiress of Sir Thomas Hyde, 2nd Baronet, of Aldbury).