Diego Laynez, S.J., born in 1512 and died on 19 January 1565 (Rome), was a Spanish Jesuit priest and theologian, a New Christian, and the second Superior General of the Society of Jesus after the founder Ignatius of Loyola.

The Society of Jesus, also known as the Jesuit Order or the Jesuits, is a religious order of clerics regular of pontifical right for men in the Catholic Church headquartered in Rome. It was founded in 1540 by Ignatius of Loyola and six companions, with the approval of Pope Paul III. The society is engaged in evangelization and apostolic ministry in 112 nations. Jesuits work in education, research, and cultural pursuits. Jesuits also conduct retreats, minister in hospitals and parishes, sponsor direct social and humanitarian ministries, and promote ecumenical dialogue.