In the Roman Catholic Church, a parish (Latin: parochus) is a stable community of the faithful within a Particular Church, whose pastoral care has been entrusted to a parish priest (Latin: pastor), under the authority of the diocesan bishop. It is the lowest ecclesiastical subdivision in the Catholic episcopal polity, and the primary constituent unit of a diocese. In the 1983 Code of Canon Law, parishes are constituted under cc. 515–552, entitled "Parishes, Pastors, and Parochial Vicars."
Most parishes are territorial parishes, which comprise all Catholics living within a defined geographic area. Some parishes may be joined with others in a deanery or vicariate forane and overseen by a vicar forane, also known as a dean or archpriest.
Per canon 518, a bishop may also erect non-territorial parishes, or personal parishes, within his see. Personal parishes are created to better serve Catholics of a particular rite, language, nationality, or other commonality which make them a distinct community. Such parishes include the following:
All Catholics who reside in a territorial parish are considered members of that territorial parish, and all members of a community for which a personal parish has been erected are similarly members of that personal parish. Membership should not be confused with registration or worship, however. Catholics are not obliged to worship only in the parish church to which they belong, but may for convenience or taste attend services in any Catholic church.
Each parish is charged to a parish priest (or pastor in the United States), although pastoral care of one or more parishes can also be entrusted to a team of priests in solidum under the direction of one of them, who is to be answerable to the bishop for their activity. In extraordinary situations, a share in the pastoral care of a parish can also be entrusted to a deacon or lay person under the supervision of a priest.