Institute of Christ the King Sovereign Priest

The Institute of Christ the King Sovereign Priest, Latin: Institutum Christi Regis Summi Sacerdotis, abbreviated as ICRSS and ICKSP, is a society of apostolic life of pontifical right in communion with the Holy See of the Catholic Church. The institute has the stated goal of honouring God and the sanctification of priests in the service of the Catholic Church and souls. An integral part of the institute's charism is the use of the traditional liturgy, namely the Tridentine Missal for Mass, the Breviary of John XXIII for the Divine Office, and the Rituale Romanum for other sacraments. The society has undertaken the restoration of a number of historic church buildings.

The institute's rule of life is based generally on that of the secular canons. Its stated mission is the defense and propagation of the reign of Christ the King in all areas of human life, both private and social.