John Williams (1582–1650) was a British clergyman and political advisor to King James I. He served as lord keeper and Archbishop of York.

Born in Wales and educated at Cambridge, he first impressed the king by a sermon in 1610. He became the king's chaplain in 1617, then lord keeper, king's advisor, and bishop of Lincoln in 1621.

Williams' relationship with Charles I was not nearly so close. In 1625 he was removed as the keeper of the great seal. Things deteriorated and in 1637 he was heavily fined by the Star Chamber, then again condemned in 1639, this time to the Tower of London. In 1641 his political career was rehabilitated and he took his seat in the House of Lords. Later that year Williams was named Archbishop of York.

When the Civil War began, he was again condemned, this time by the House of Commons for his support of the Royalist cause. But by 1646 he had shifted his support to the Parliamentary side. He died on March 28, 1650.