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. 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 Council of Thirty 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.
Guilford sat as a judge at some of the Popish Plot trials, and all like his judicial colleagues who did so 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, so dominated the proceedings 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".
Guilford was hostile to Lord Jeffreys, and regarded the future Lord Chief Justice, Sir Robert Wright, as utterly unfit for any judicial office (he was well qualified to assess Wright's ability since Wright as a young barrister had relied on North to write his legal opinions for him). He has been criticised for remaining in office after Wright was made Chief Justice over his vehement objections, especially as it must have been clear that he no longer had any influence over judicial appointments. On the other hand, he may have felt that keeping Jeffreys out of the Lord Chancellorship was a sufficient justification for clinging to office.