Charles Journet studied at the seminary in Fribourg before being ordained to the priesthood on 15 July 1917. He did pastoral work in the Diocese of Fribourg until 1924 and taught at the seminary from 1924 to 1965.
Journet was raised to the rank of Domestic Prelate of His Holiness on 13 August 1946 by Pope Pius XII. On February 15, 1965, he was appointed as the Titular Archbishop of Furnos Minor by Pope Paul VI, and he received his episcopal consecration on February 20, 1965. Two days later, he was elevated to the College of Cardinals by Pope Paul VI, becoming the Cardinal-Deacon of Santa Maria in Campitelli.
Journet was a close friend of the renowned philosopher Jacques Maritain, with whom he founded the theological journal "Nova et Vetera" in 1926.