member of either of two Roman Catholic religious congregations, one of men and one of women, devoted to the Christian education of youth, especially the less privileged.

The founder of the Salesians of Don Bosco (formally, the Society of St. Francis de Sales; S.D.B.) was St. John Bosco (Bosco, Saint John) (Don Bosco), a young priest who focused his concern on the orphaned and homeless child labourers whom he encountered in Turin, Italy. In 1859, inspired by the example of St. Francis de Sales, Don Bosco founded the Salesians to befriend, educate, and help these impoverished boys. Thirty years later, at the time of Don Bosco's death, the original group of 17 members had grown to more than 1,000 and had 57 foundations in Italy, Spain, France, England, Uruguay, and Brazil. The congregation continued to spread so rapidly that it soon became the third largest among men's orders. Its works have expanded to include trade, agricultural, and academic schools; seminaries; recreational centres and youth clubs in large cities; summer camps; and parishes.

The Salesian Sisters (formally, the Daughters of Mary Help of Christians; F.M.A.) are one of the largest Roman Catholic religious congregations of women, founded in 1872 at Mornese, Italy, by St. John Bosco and St. Mary Mazzarello. Like their male counterparts, the sisters followed Don Bosco's norms for education: reason, religion, and amiability and the employment of all that is humanly useful in character formation—academic studies, manual skills, work, clubs, and athletic games.