John Ker, 1st Duke of Roxburghe, KG, PC, FRS was a Scottish nobleman.

The Duke of Roxburghe is a title in the peerage of Scotland created in 1707 along with the titles Marquess of Bowmont and Cessford, Earl of Kelso and Viscount Broxmouth. John Ker, 5th Earl of Roxburghe became the first holder of these titles. The title is derived from the royal burgh of Roxburgh in the Scottish Borders that in 1460 the Scots captured and destroyed.