The Passionists, officially named the Congregation of the Passion of Jesus Christ (Latin: Congregatio Passionis Iesu Christi), abbreviated CP, are a Catholic clerical religious congregation of pontifical right for men, founded by Paul of the Cross in 1720, with a special emphasis on and devotion to the Passion of Jesus Christ. A known symbol of the congregation is the labeled emblem of the Sacred Heart of Jesus, surmounted by a cross. This symbol is often sewn into the attire of its congregants.

Paul of the Cross, who was born in 1694 in Ovada, wrote the rules of the Congregation between 22 November 1720 and 1 January 1721. On 7 June 1725, Pope Benedict XIII granted Paul permission to form his congregation. Paul and his brother, John Baptist Danei, were ordained by the pope on the same occasion.

After serving for a time in the hospital for skin diseases of St. Gallicano, in 1737 they left Rome with permission of the pope and went to Mount Argentario, where they established the first house of the institute. They took up their abode in a small hermitage near the summit of the mount, to which was attached a chapel dedicated to Saint Anthony. They were soon joined by three companions, one of whom was a priest, and the observance of community life according to the rules began there and is continued there to the present day. Paul of the Cross and his companions – now totalling six priests and two brothers – began a retreat.

In 1769, Clement XIV granted full rights to the Passionists as enjoyed by the other religious institutes, making them not an order but a congregation. The congregation historically has had two primary goals: Preaching Missions and contemplative life, with an attempt to blend the two. Its founder had attempted to combine aspects of the contemplative orders, such as the Trappist monks, together with the dynamic orders, such as the Jesuits.

Both the members and the works of the congregation are entrusted to the protection of the Blessed Virgin Mary under the title of Our Lady of Sorrows, as patroness of the congregation, with Saint Michael and Saint Joseph as co-patrons. Every Passionist religious is required to honour them, together with the founder, Paul of the Cross, and the other saints of the congregation, whose feasts they celebrate in community.

On 11 June 1741, they first affixed the emblem or "sign" of the Passion (Jesu XPI Passio) on their black tunics. The professed renewed their vows, and the new members pronounced their first vows.

The Passionate charism "[seeks] the unity of our lives and our apostolate in the Passion of Jesus." The Passionate express their participation in the Passion by a special vow, by which they bind themselves to keep alive the memory of the Passion of Christ. They strive to foster awareness of its meaning and value for each person and for the life of the world. They seek to incorporate this vow into their daily lives by living the evangelical counsels of poverty, chastity and obedience.

Traditionally, their main apostolate has been preaching missions and retreats. According to Paul of the Cross, they were founded in order to "teach people how to pray", which they do through activities such as retreats and missions, spiritual direction, and prayer groups. Today they often also assist local churches in pastoral works, including saying masses, hearing confessions, and visiting the sick. Due to the continuing shortage of priests throughout the world, the Passionists today are sometimes designated as parish priests and curates of various parishes. The Passionists hold many retreat and conference centers around the world.