Leon Gustav Dehon (14 March 1843–12 August 1925) was a Catholic clergyman.
Born in gustav (Soissons), France, Dehon was raised in a family, Leo Dehon's mother was especially devoted to the Sacred Heart, and passed this on to Leo. As a young man he felt a call to the priesthood, but his father had other plans for him, and sent him to study at the Sorbonne in Paris. He earned a degree in civil law at 21, but had spent much of his free time in a local church. His father tried again to interest his son in the world by sending him on a long tour of the East, but on his way home Leo entered the French Seminary of Saint Claire in Rome in October 1865. He was ordained on 19 December 1868 in the basilica of Saint John Lateran. His father not only came to terms with his son's vocation, he returned to the Church himself.
Fr. Dehon acted as stenographer for Vatican I, and was a parish priest at Saint Quentin. Father Leo began feeling drawn to religious life, and on 28 June 1878, following a pilgrimage to Loreto, Italy, he founded the Oblates of the Sacred Heart, taking the name Father John of the Sacred Heart. The Oblates grew quickly, but due to misunderstandings about their mission, they acquired great opposition, and on 3 December 1883 the order was compelled to disband. After a period of depression, prayer and reflection, Leo re-formed the order as the Priests of the Sacred Heart (Dehonians) on 25 February 1888 with a goal of parish and foreign missionary work, with special devotion of its members to Eucharistic adoration. They received the approval of Pope Leo XIII who asked "Father John" to preach on the basis of one of the pope's encyclicals. He started the Reign of the Sacred Heart magazine in 1889. Though they had the support of Pope Leo XIII, Pope Pius X, Pope Benedict XV, and Pope Pius XI, he and his priests continued to be accused of slander and various other charges for years. He participated in congresses and conferences, founded new houses of the Priests, and heard confessions for long hours at a time. He began the construction of the Basilica of Christo Re beginning on 18 May 1920. He died of natural causes on 12 August 1925 in Brussels, Belgium.
Father Leo Dehon was declared venerable in 1997 by Pope John Paul II. His beatification is pending, following having received the approval of the Congregation for the Causes of Saints on 19 April 2004. It was originally scheduled for 24 April 2005, but was delayed initially due to the death of Pope John Paul II on 2 April 2005. A hold on the beatification has been announced due to a re-examination of his written works in response to charges of anti-semitism levied by a number of individuals and organizations, both clerical and secular.
- Alan Cooperman (16 June 2005). "Pope Halts Beatification of French Priest". Washington Post.
- Priests of the Sacred Heart USA
- Leon Dehon's letters and archives inventory