John Kastner (1946 – November 21, 2019) was a four-time Emmy Award-winning Canadian documentary filmmaker whose later work focused on the Canadian criminal justice system. His films included the documentaries Out of Mind, Out of Sight (2014), a film about patients at the Brockville Mental Health Centre, named best Canadian feature documentary at the Hot Docs Canadian International Documentary Festival; NCR: Not Criminally Responsible (2013), exploring the personal impact of the mental disorder defence in Canada; Life with Murder (2010), The Lifer and the Lady and Parole Dance, and the 1986 made-for-television drama Turning to Stone, set in the Prison for Women in Kingston, Ontario.