A cleric (Ancient Greek κληρικός - klērikos), clergyman (pl. clergymen), or churchman (pl. churchmen) is a member of the clergy of a religion, especially one who is a priest, preacher, or other religious professional. It is often used to refer to the religious leadership in Islam, where the term "priest" is not accurate and where terms such as "Alim" are not widely understood in the English-speaking world.

Within Christianity, especially in Eastern Christianity and formerly in Western Roman Catholicism, the term cleric refers to any individual who has received the clerical tonsure, including deacons, priests, and bishops. - Catholic Encyclopedia In Latin Roman Catholicism, the tonsure was a prerequisite for receiving any of the minor orders or major orders before the tonsure, minor orders, and the subdiaconate were abolished following the Second Vatican Council. Now, the clerical state is tied to reception of the diaconate. Minor Orders are still given in the Eastern Catholic Churches, and those who receive those orders are 'minor clerics.'

To use cleric is also appropriate for Eastern Orthodox minor clergy who are tonsured in order not to trivialise orders such as those of Reader in the Eastern Church, or for those who are tonsured yet have no minor or major orders. It is in this sense that the word entered the Arabic language, most commonly in Lebanon from the French, as "kleriki" (or, alternately, "cleriki") meaning "seminarian." This is all in keeping with Eastern Orthodox concepts of clergy, which still include those who have not yet received, or do not plan to receive, the diaconate.

The term "clerk" derives from "cleric," since in medieval times the clergy were one of the few groups who could read, and therefore were often employed to do bookkeeping and similar work. The term clerical work continues to this day to refer to such functions.