Earl of Guilford is a title that has been created three times in history. The title was created for the first time in the Peerage of England in 1660 (as Countess of Guilford) for Elizabeth Boyle. She was a daughter of William Feilding, 1st Earl of Denbigh, and the widow of Lewis Boyle, 1st Viscount Boyle of Kinalmeaky. The title was for life only and became extinct on her death in 1667. The title was created for a second time in the Peerage of England in 1674 for John Maitland, 1st Duke of Lauderdale. For more information on this creation, see the article on him as well as the Earl of Lauderdale.
Despite the first two creations, the title of Earl of Guilford is chiefly associated with one branch of the North family, which descends from the Hon. Sir Francis North, second son of Dudley North, 4th Baron North (see the Baron North for earlier history of the family), a lawyer and politician. He was Chief Justice of the Common Pleas from 1675 to 1682 and Lord Keeper of the Great Seal from 1682 to 1685. In 1683 he was created Baron Guilford, of Guilford (now spelled Guildford) in the County of Surrey, in the Peerage of England. He died in middle age and was succeeded by his son, the second Baron, who briefly served as President of the Board of Trade from 1713 to 1714 and was also Lord-Lieutenant of Essex. His son, the third Baron, represented Banbury in the House of Commons of Great Britain. In 1734 he succeeded his cousin as seventh Baron North and in 1752 was honoured by being created Earl of Guilford in the Peerage of Great Britain.