William Walwyn (bap. 1600–1681) was an English pamphleteer, a Leveller and a medical practitioner.
Walwyn was a silkman in London who took the parliamentary side in the English Civil War. He advocated religious toleration and emerged as a leader of the Levellers in 1647 which led to his imprisonment in 1649. During 1646 he wrote five pamphlets in response to Thomas Edwards' Gangraena in which Walwyn was described as "a Seeker, a dangerous man, a strong head". In 1649, whilst held in the Tower of London on a charge of Treason, he published "The Fountain of Slaunder Discovered" and "Walwyns Just Defence" to defend his character against the publication of "Walwyn's Wiles". The pamphlet had seven authors who were the leading Baptist and Independent preachers in London at the time Arnald, Burnet, Foster, Kiffin, Lordall, Price, and Rosier, but was mainly drafted by John Price who had previously attack Walwyn in print after four of the Leveller petitions were burnt by the common hangman in June 1647 (see "Gold Tried in the Fire"). In Price's opinion it was Walwyn not Lilburne who was the most dangerous of the Leveller leaders. In 1653 when Lilburne was arrested having returned from exile in Bruges, Overton and Prince rallied support, Walwyn however was arrested and held in the tower until after Lilburne's trial was concluded.
This pamphlet was written by seven of the leading London Independent and Baptist preachers and published whilst Walwyn and the other Leveller leaders were held in the tower. The full title was "Walwyn's Wiles, or the Manifestators manifested, ... declaring the subtle and crafy wiles, the atheistical, blasphemous soul-murdering principles and practices of Mr William Walwyn". Walwyn's Wiles was a response to the jointly signed Leveller pamphlet "A Manifestation" (April 14, 1649) which whilst it denied that they intended to level men's estates also stood firm on the principles outlined in The Agreement of the People.