John Leonardi, OMD was an Italian Catholic priest and the founder of the Clerics Regular of the Mother of God of Lucca.

The Clerics Regular of the Mother of God is a religious order of clerics regular of pontifical right. Its priests are dedicated to education and pastoral care. The Order was founded by St. John Leonardi, who worked with this congregation to spread devotion to the Blessed Virgin Mary, as well as the Forty Hours devotion, and frequent reception of the Blessed Sacrament.