The Society of Jesus (Latin: Societas Iesu; abbreviation: SJ), commonly known as the Jesuits (; Latin: Iesuitæ), 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.

The Society of Jesus is consecrated under the patronage of Madonna della Strada, a title of the Blessed Virgin Mary, and it is led by a Superior General. The headquarters of the society, its General Curia, is in Rome. The historic curia of Ignatius is now part of the Collegio del Gesù attached to the Church of the Gesù, the Jesuit mother church.

Members of the Society of Jesus are expected to accept orders to go anywhere in the world, where they might be required to live in extreme conditions. This was so because Ignatius, its leading founder, was a nobleman who had a military background. Accordingly, the opening lines of the founding document declared that the society was founded for "whoever desires to serve as a soldier of God, to strive especially for the defense and propagation of the faith, and for the progress of souls in Christian life and doctrine". Jesuits are thus sometimes referred to colloquially as "God's soldiers", "God's marines", or "the Company". The society participated in the Counter-Reformation and, later, in the implementation of the Second Vatican Council.

Jesuit missionaries established missions around the world from the 16th to the 18th century and had both successes and failures in Christianizing the native peoples. Beginning in 1759, the Catholic Church expelled Jesuits from most countries in Europe and from European colonies. In 1814, the Church lifted the suppression.