Sebastiano Valfrè was born to a poor Piedmontese peasant family at Verduno, supported by his uncle in Turin for his initial schooling, and entered the Turin Oratory (the Italian Oratorian congregation founded by Philip Neri a century before, established at Turin in 1649) in 1651 at twenty-two. He was ordained priest in 1652 and remained at the Turin Oratory for the next fifty-eight years.
He was the principal confessor and spiritual director of the Savoy court for over forty years — through the reigns of Carlo Emanuele II, Victor Amadeus II, and the early reign of Victor Amadeus's son Charles Emmanuel III. He confessed Victor Amadeus II personally (the Savoy duke who became King of Sicily and then of Sardinia, the most consequential Italian sovereign of the early 18th century) and the royal family weekly for over thirty years. He was credited with the supernatural relief of the great Turin siege of 1706 — when Prince Eugene of Savoy's relief army broke the French and Spanish siege of the city, ending the threat to the Italian peninsula in the War of the Spanish Succession.
He served the Turin poor of his Oratorian parish indefatigably — the parish records show him visiting between twenty and forty homes per day for fifty years. He died at the Turin Oratory on January 30, 1710. Beatified 1834.