Born in Saint-Louis de Lotbinière, Louis-Philippe Beaudet studied in Nicolet before pursuing his training in Saint-Laurent. In 1865, he entered the Congrégation de Sainte-Croix and became a priest three years later. After officiating in the Parish of Saint-Bruno in the Diocese of Saint-Jean, he was elected Superior of collège de Saint-Laurent in 1871. He thereby became the first French Canadian to direct this institution, and this until 1873, when he was entrusted with the responsibility of heading the Parish of Grande-Digue, in New Brunswick.
When in 1876 Father Félix Véniard left the Parish of Saint-Laurent to go to the United States, Father Beaudet returned to Saint-Laurent, this time as Parish Priest, a position he held for more than twenty years. During his time in office, he completed a series of projects including the development of a new cemetery in the rear-most section of land left for use by the Parish Priest, and restoration and embellishment of Saint-Laurent Church (reconstruction of the façade in 1884 and complete restoration in 1895).
Father Philippe Beaudet