Oratory of Saint Philip Neri

The Confederation of Oratories of Saint Philip Neri (Latin: Confoederatio Oratorii Sancti Philippi Nerii), abbreviated C.O. and commonly known as the Oratorians, is a Catholic society of apostolic life of pontifical right for men (priests and religious brothers) who live together in a community bound together by no formal vows but only with the bond of charity.

Founded in Rome in 1575 by Philip Neri, today it has spread around the world, with over 70 Oratories and some 500 priests. The post-nominal initials commonly used to identify members of the society are "CO" (Congregatio Oratorii). The abbreviation "Cong. Orat." is also used.

Unlike a religious institute (the members of which take vows and are answerable to a central authority) or a monastery (the monks of which are likewise bound by vows in a community that may itself be autonomous and answerable directly to the pope), the Oratorians commit themselves to membership in a particular, independent, self-governing local community (an Oratory, usually named for the place in which it is located: e.g., Birmingham Oratory, Oxford Oratory, Brooklyn Oratory) without actually taking vows, an unusual and innovative arrangement created by Philip. Normally an oratory must have a minimum of four members, two being ordained, in order to be founded. If a group of men seeks to establish an oratory, they may apply to do so, going through the proper diocesan channels; during the process of formation a member (or members) of a well-established oratory resides in the community to facilitate every aspect of the proposed foundation.