Born in Philadelphia, Pennsylvania, in 1920, Fitzmyer was admitted, on July 30, 1938, to the novitiate of the Maryland Province of the Society of Jesus, commonly known as the Jesuits, in Wernersville, Pennsylvania. After completing that stage of his formation in the summer of 1940, he was sent to study at Loyola University in Chicago, Illinois, earning a Bachelor of Arts degree and then, in 1945, a Master of Arts degree in Greek. He then studied theology in the Facultés Saint-Albert (Egenhoven–Louvain), Belgium, and was ordained a Catholic priest on August 15, 1951. He was granted a Licentiate of Sacred Theology (S.T.L.) by the Catholic University of Leuven in 1952, a doctorate in Semitics from the Johns Hopkins University in 1956, and a Licentiate in Sacred Scripture (S.S.L.) from the Pontifical Biblical Institute in Rome in 1957.