Fr. Joseph Fessio SJ is an American Catholic priest of the Jesuit order and the founder and editor of Ignatius Press.

In 1974 Father Joseph Fessio, S.J. returned to the United States from then-West Germany, where he had completed his doctoral studies in theology under then-Professor Joseph Ratzinger (who would later become Pope Benedict XVI).  It was to serve the good of the Catholic Church by making these works available to English-speaking readers, that in June of 1978, Father Fessio, along with Carolyn Lemon, began Ignatius Press as the primary activity of an existing non-profit religious corporation, Guadalupe Associates, Inc. Ignatius Press also undertook to assist in the religious education of young people through collaborating with Catholics United for the Faith to develop the Faith and Life series and with a catechetical group to produce a catechetical series Image of God.

Later, Father Fessio and Ignatius Press assisted with the English translation of the Catechism of the Catholic Church. More recently, Ignatius Press published the YOUCAT series of books aimed at the religious formation of young people. These works were created with the help of an international group of youth and catechists, and were approved by Popes Benedict and Francis.