Born: June 30, 1971 in Montreal
Priestly Ordination: December 14, 1996
Episcopal Ordination: September 12, 2022
Motto: ‘'Do whatever he tells you'

Born in Montreal in 1971 to Italian immigrant parents Francesco Leo and †Rosa Valente, Archbishop Leo attended Eugenio Pacelli Elementary School, John F. Kennedy High School and CEGEP Vanier. He then entered the Grand Séminaire de Montréal in 1990 and was ordained a priest for service to the Archdiocese of Montreal on 14 December 1996. He served in different parish assignments in Montréal (assistant pastor at Our Lady of Consolata, parochial administrator of Saint-Joseph-de-RDP, and pastor of Saint-Raymond-de-Peñafort) until 2006 when he accepted the invitation to enroll in the Pontifical Ecclesiastical Academy in Rome and subsequently enter the Diplomatic Service of the Holy See (2006-2012), serving in different Apostolic Nunciatures across the globe. On 9 January 2012, Pope Benedict XVI appointed him Chaplain of His Holiness, bestowing the title of Monsignor.

Upon his return to Canada, he joined the formation team of the Grand Séminaire de Montréal, teaching theology and philosophy while providing spiritual direction, formation and accompaniment to the candidates for the priesthood. In the fall of 2015 he was appointed General Secretary of the Canadian Conference of Catholic Bishops (CCCB), a mandate which came to an end in the fall of 2021. As of February 1st 2022, Archbishop Leo was named Vicar General and Moderator of the Curia of the Archdiocese of Montreal.

In addition to his extensive graduate studies in Canon Law (Pontifical Lateran University), Diplomacy and International Law, Archishop Leo holds a Doctorate in Systematic Theology (University of Dayton ⁄ IMRI) with a specialization in Mariology, a Licentiate in Philosophy (Pontifical Lateran University), a Diploma in Classical Studies (Université de Montréal) and a Graduate Certificate in Spiritual Direction (Aquinas Institute of Theology). He worked as a Judge for the Canadian Appeal Tribunal and has taught theology, spirituality and philosophy at Montreal, Canberra (Australia), Dayton (USA) and Ottawa, among other places. He speaks English, French, Italian and Spanish. Archbishop Leo is President and founding member of the Canadian Mariological Society, Knight of the Equestrian Order of the Holy Sepulchre of Jerusalem as well as a member of the Priestly Fraternity of St. Domenic (Third Order Dominican).

Archbishop Leo was appointed by the Holy Father Titular Bishop of Tamada and Auxiliary Bishop of Montreal on July 16, 2022, and was ordained to the Episcopacy on September 12, 2022. Archbishop Leo was named as the Archbishop of Toronto on Saturday, February 11, 2023 by Pope Francis. He was installed as Archbishop on Saturday, March 25, 2023.