In the canon law of the Catholic Church, the loss of clerical state (commonly referred to as laicization, dismissal, defrocking, and degradation) is the removal of a bishop, priest, or deacon from the status of being a member of the clergy.

The term defrocking originated in the ritual removal of vestments as a penalty against clergy that was eventually codified within the Roman Pontifical. Contemporary Latin Catholic canon law does not contain such a ritual, leading some to consider it an inaccurate description of laicization. However, others consider "defrocking" a synonym to laicization that is especially popular in English. While the ritual removal of the vestments no longer exists, canon law still prohibits the wear of a clerical collar by laicized priests.

In the Catholic Church, a bishop, priest, or deacon may be dismissed from the clerical state as a penalty for certain grave offences, or by a papal decree granted for grave reasons. This may be because of a serious criminal conviction, heresy, or similar matter. Removal from the clerical state is sometimes imposed as a punishment (Latin: ad poenam), or it may be granted as a favour (Latin: pro gratia) at the cleric's own request. A Catholic cleric may voluntarily request to be removed from the clerical state for a grave, personal reason. Voluntary requests were, as of the 1990s, believed to be by far the most common means of this loss, and most common within this category was the intention to marry, as most Latin Church clergy must as a rule be celibate. Canon law was amended in March 2019 to allow dismissal from their community, though not dismissal from the clerical state, for religious who are members of, and desert, a religious community. This policy has been in force since 10 April 2019.