On October 29, 1855, Paul Bruchési, son of Paul-Dominique Bruchési and Caroline Aubry, was born in the parish of Saint-Joseph in Montreal, which was then considered to be the neighbour of the future Cathedral. He was part of a family of seven children; another of his brothers, Barthélemy, also became a priest; another, Benjamin, a lawyer.

He did his classical studies at the Collège de Montréal, his philosophy at the Séminaire d'Issy-les-Moulineaux, near Paris, his theology and canon law in Rome, at the Séminaire français, at the Collège romain, and concluded at the Apollinaire from where he obtained a doctorate in theology and a doctorate in canon law.

He received priestly ordination in the Basilica of St John Lateran on December 21, 1878 from Cardinal Rafaele Monaco La Valetta. Among the others ordained was Giacomo Della Chiesa, who became Pope Benedict XV.

Back in Montreal in 1879, he was appointed private secretary to Msgr. Fabre. From 1880 to 1884, he was a professor of dogma at Laval University in Quebec City. Returning to Montreal in 1885, he was successively vicar in the parishes of Saint-Joseph and Sainte-Brigide. In 1887, he became the director of the diocesan magazine, then called La Semaine religieuse. In September of the same year, he taught a course in apologetics at Laval University in Montreal.

In 1891, Msgr. Fabre appointed him titular canon of the Cathedral. On Easter Sunday, March 24, 1894, on the occasion of the official opening of Saint-Jacques Cathedral, Msgr. Fabre entrusted him with the task of giving the first sermon in the new Cathedral before a large audience.