Francis North, 1st Baron Guilford PC KC(22 October 1637 – 5 September 1685) was the third son of Dudley North, 4th Baron North, and his wife Anne Montagu, daughter of Sir Charles Montagu and Mary Whitmore. He was created Baron Guilford in 1683, after becoming Lord Keeper of the Great Seal in succession to Lord Nottingham.
Francis North was educated at St John's College, Cambridge. He was an eminent lawyer, Solicitor-General (1671), Attorney-General (1673), and Chief Justice of the Common Pleas (1675), and in 1679 was made a member of the Privy Council Ministry and, on its dissolution, of the Cabinet. He was a man of wide culture and a staunch royalist, although he opposed the absolutist tendencies of Sunderland and Jeffreys, his two bitterest political enemies. He was a strong supporter of the royal prerogative, remarking that he did not see how any good and honest lawyer could oppose it, as all the precedents were in its favour.
Guilford sat as a judge at some of the Popish Plot trials, and like his colleagues he has been accused of excessive credulity in believing the absurd lies of Titus Oates and the other informers. On the other hand, it has been argued that the senior Chief Justice, Sir William Scroggs, entirely dominated the proceedings so that none of the other judges had any influence on the outcome. If North succumbed to the prevailing hysteria, so did many others: his brother Roger wrote that "it was a time when wise men behaved like stark fools".