John J. Castelot, S.S. (August 26, 1916 – May 14, 1999) was an American Roman Catholic priest, Sulpician, teacher, and writer.

[2] Later on he did graduate studies at the Catholic University of America, Washington, D.C. and at the Pontifical Biblical Institute in Rome.

After his studies, John J. Castelot was teacher of Sacred Scripture, Greek, Hebrew, and Sacred Music at the St. John's Provincial Seminary, in Plymouth, Michigan, but he also taught at St Joseph's College, Mountain View, California and at the Sulpitian Novitiate in Baltimore, Maryland.

He wrote the voices "Gentiles", "St. Peter Apostle", and "Gerard Van Noort" for the New Catholic Encyclopedia.

For The Jerome Biblical Commentary (1968), he wrote, in collaboration with Aelred Cody, the chapter "Religious institutions of Israel".