The minor orders were formally a part of the clergy of the Roman Catholic Church. During the Counter-reformation, the Council of Trent decided to formally define seven "Orders" of the clergy. After induction into the clerical state through the tonsure, a seminarian could receive the first four, which were the minor orders. They consisted of:

• porter (or doorkeeper),
• lector,
• exorcist, and
• acolyte.

These four were called "minor orders" because perpetual celibacy was not a requirement for them. If a seminarian quit the seminary before becoming a subdeacon, he could still get married. After receiving all the minor orders, a seminarian could receive the major orders.

None of the minor orders were a part of the sacrament of Holy Orders, but were instead viewed as preparatory offices. This system was abolished after the Second Vatican Council by Paul VI, though candidates for the priesthood must still receive the "ministries" of lector and acolyte before ordination. The duties formerly performed by members of the minor orders are now usually performed by the laity; see Catholic minister.

See also Holy Orders.