A '''catechumen''' (gr. κατηκουμενοςGreek: κατηχούμενος) is one who is preparing for [[baptism]] in the Church. In modern usage, ''catechumen'' can also refer to one who is preparing for [[chrismation]] (or another form of reception) to be received from a [[heterodox]] Christian communion.

In the ancient Church, the catechumenate, or time during which one is a catechumen, often lasted for as much as three years and included not only participation in the divine [[services]] but also '''catechesis''', formal instruction from a teacher, often the [[bishop]] or appointed '''catechist'''. [[Exorcist]]s often performed the catechetical role, as well, following their initial prayers of [[exorcism]] over the one being made a catechumen, which is the traditional manner of receiving a catechumen into the community of the Church.