Douglas was the second son of William Douglas, 1st Earl of March and his wife Lady Jane Hay, second daughter of John Hay, 1st Marquess of Tweeddale.
[1] Douglas was returned unopposed as Member of Parliament for Peebleshire at the 1722 British general election on the interest of his brother, the 2nd Earl of March.
[1] Following the death of his brother William, 2nd Earl of March, in 1731, John Douglas was appointed guardian to his seven-year-old nephew, William, 3rd Earl of March, who later became the 4th Duke of Queensberry.
He was so deeply in debt that his estates were sold in 1736 to pay his creditors.
This article about a Member of the Parliament of Great Britain (1707–1800) representing a Scottish constituency is a stub.