In the Catholic Church, a secular institute is a type of institute of consecrated life in which consecrated persons profess the Evangelical counsels of celibate-chastity, poverty and obedience while living in the world, unlike members of a religious institute who live in community. Secular institutes represent a form of consecration in secular life, not religious life. It is one of the forms of consecrated life recognized in Church law (1983 Code of Canon Law, Canons 710–730):
A secular institute is an institute of consecrated life in which the Christian faithful living in the world strive for the perfection of charity and work for the sanctification of the world especially from within.
Secular institutes first received papal recognition from Pope Pius XII in Provida Mater Ecclesia (1947). Secular institutes are recognized either by a bishop (diocesan right) or by the Holy See. Most are registered in the World Conference of Secular Institutes. There are nine secular institutes in the UK. These institutes belong to the National Conference of Secular Institutes (NCSI). This is an association for co-operation and mutual support of those secular institutes which have membership in the United Kingdom. The NCSI is affiliated to the Conference Mondiale des Instituts Seculiers (CMIS) which represents all secular institutes in the world.
Currently, up to 32,000 members belong to more than 184 secular institutes in the world. Most of the members of secular institutes are lay people. Some join as diocesan priests or deacons, and some institutes are founded specifically for diocesan priests who wish to take vows and lead a consecrated life while still being incardinated in their diocese and working in the diocesan framework. Some secular institutes even train and incardinate their own priests.
Notable secular institutes
- Secular Institute Pius X (I.S.P.X.)
- Institute of the Maids of the Poor (M.O.P.)
- Company of St. Ursula
- Schoenstatt Apostolic Movement
- Secular Institute Madonna della Strada
- Caritas Christi 
- Institute of the Priests of the Heart of Jesus 
- Concerning Secular Institutes in the Code of Canon Law (1983), can. 710–730
- United States Conference of Secular Institutes
- World Conference of Secular Institutes
- Provida Mater Ecclesia at the Vatican website