Joan Bocher (died 2 May 1550 Smithfield, London) was an English Anabaptist burned at the stake for heresy. She has also been known as Joan Boucher or Butcher, or as Joan Knell or Joan of Kent. Bocher's origins are unclear, but it is known that families named Bocher and Knell lived in the area round Romney Marsh. She was associated with Baptists and Anabaptists in Kent, some of them immigrants who had fled persecution in the low countries. In the 1530s and 1540s she was "much in favour in reforming circles" in Canterbury. Although there is a lack of definitive written evidence, there are long-standing traditions associating her with Eythorne Baptist Church.