John Douglas Main OSB (21 January 1926 – 30 December 1982) was a Roman Catholic priest and Benedictine monk who presented a way of Christian meditation which used a prayer-phrase or mantra. In 1975, Main began Christian meditation groups which met at Ealing Abbey, his monastery in West London, England, and, later, in Montreal, Quebec, Canada. These were the origins of the ecumenical network of Christian meditation groups which have become the World Community for Christian Meditation (WCCM).
