Louis-Marie Grignion de Montfort, SMM (; 31 January 1673 – 28 April 1716) was a French Catholic priest known for his influence on Catholic Mariology. He wrote a number of books that went on to become classic Catholic titles, including ''Secret of the Rosary'' and ''True Devotion to Mary'', and influenced several popes. He also founded several religious communities, including the Company of Mary.