According to the Tridentine dogmas of Catholicism, a sacramental character is an indelible supernatural mark made on a person's soul by any of three of the seven sacraments: baptism, confirmation, and holy orders. The characters imprinted by those three sacraments are held to differ from each other. Each character is held to remain indelible during the recipient's life, and therefore each of those three sacraments may be received only once. In case of doubt about whether a person has received one of these three sacraments, the sacrament may be administered conditionally. In the case of holy orders, a man who has been ordained a deacon may be ordained a priest, but may not again be ordained a deacon; similarly a priest may be ordained a bishop but may not again be ordained a priest, and a bishop may not receive any further holy orders. Theologians differ on the question of whether the episcopal character is merely an extension of the presbyteral character, or is separate from it. Catholic dogmas do not state whether sacramental characters continue indelible after death, although theologians consider it very probable.

Although the doctrine of sacramental characters was not dogmatically defined until the Council of Trent met in the 16th century, it is is at least 1000 years older than that, having been written about by Augustine of Hippo.