The Latin Church (Latin: Ecclesia Latina) is the largest autonomous (sui iuris) particular church within the Catholic Church, whose members constitute the vast majority of the 1.3 billion Catholics. The Latin Church is one of 24 sui iuris churches in full communion with the pope; the other 23 are collectively referred to as the Eastern Catholic Churches, and they have approximately 18 million members combined.

The Latin Church is directly headed by the pope in his role as the bishop of Rome, whose cathedra as a bishop is located in the Archbasilica of Saint John Lateran in Rome, Italy. The Latin Church both developed within and strongly influenced Western culture; as such, it is sometimes called the Western Church (Latin: Ecclesia Occidentalis), which is reflected in one of the pope's traditional titles in some eras and contexts, the Patriarch of the West. It is also known as the Roman Church (Latin: Ecclesia Romana), the Latin Catholic Church, and in some contexts as the Roman Catholic Church (though this name can also refer to the Catholic Church as a whole).

The Latin Church was in full communion with what is referred to as the Eastern Orthodox Church until the East–West Schism of Rome and Constantinople in 1054. From that time, but also before it, it became common to refer to Western Christians as Latins in contrast to Byzantines or Greeks.

The Latin Church employs the Latin liturgical rites, which since the mid-20th century are very often translated into the vernacular. The predominant liturgical rite is the Roman Rite, elements of which have been practiced since the fourth century. There exist and have existed since ancient times additional Latin liturgical rites and uses, including the currently used Mozarabic Rite in restricted use in Spain, the Ambrosian Rite in parts of Italy, and the Anglican Use in the personal ordinariates.

In the early modern period and subsequently, the Latin Church carried out evangelizing missions to the Americas, and from the late modern period to Sub-Saharan Africa and East Asia. The Protestant Reformation in the 16th century resulted in Protestantism breaking away, resulting in the fragmentation of Western Christianity, including not only Protestant offshoots of the Latin Church, but also smaller groups of 19th-century break-away Independent Catholic denominations.

The historical part of the Catholic Church in the West is called the Latin Church to distinguish itself from the Eastern Catholic Churches which are also under the pope's primacy. In historical context, before the East–West Schism in 1054 the Latin Church is sometimes referred to as the Western Church. Writers belonging to various Protestant denominations sometime use the term Western Church as an implicit claim to legitimacy.^{[clarification needed]}

The term Latin Catholic refers to followers of the Latin liturgical rites, of which the Roman Rite is predominant. The Latin liturgical rites are contrasted with the liturgical rites of the Eastern Catholic Churches.

The 1990 Code of Canons of the Eastern Churches defines the use within that code of the words "church" and "rite". In accordance with these definitions of usage within the code that governs the Eastern Catholic Churches, the Latin Church is one such group of Christian faithful united by a hierarchy and recognized by the supreme authority of the Catholic Church as a sui iuris particular Church. The "Latin Rite" is the whole of the patrimony of that distinct particular church, by which it manifests its own manner of living the faith, including its own liturgy, its theology, its spiritual practices and traditions and its canon law. A Catholic, as an individual person, is necessarily a member of a particular church. A person also inherits, or "is of", a particular patrimony or rite. Since the rite has liturgical, theological, spiritual and disciplinary elements, a person is also to worship, to be catechized, to pray and to be governed according to a particular rite.