In the Catholic Church, a member of the clergy who is created a cardinal is assigned a titular church in Rome, Italy. These are Catholic churches in the city, within the jurisdiction of the Diocese of Rome, that serve as honorary designations signifying the relationship between cardinals and the pope, the bishop of Rome.^[1][2] According to the Code of Canon Law, a cardinal may assist his titular church through counsel or patronage, although "he has no power of governance over it, and he should not for any reason interfere in matters concerning the administration of its good, or its discipline, or the service of the church".^[3]

There are two ranks of titular churches: titles and deaconries. A title (Latin: titulus) is a titular church that is assigned to a cardinal priest, whereas a deaconry (Latin: diaconia) is normally assigned to a cardinal deacon.^{[lower-alpha 1][3]} A cardinal may request that he be transferred to another titular church in a consistory; in addition, when a cardinal deacon opts to become a cardinal priest (usually after ten years), he may request either that his deaconry be elevated pro hac vice ('for this occasion') to a title or that he be transferred from his deaconry to a vacant title.^[2][3] Occasionally, a titular church may be retained in commendam ('in trust') by a cardinal who has been transferred to another titular church or a suburbicarian diocese.^[2][5]

If a cardinal priest or a cardinal deacon is later made a cardinal bishop, he may be transferred from his deaconry or titular church and assigned the title of a suburbicarian diocese in the vicinity of Rome.^{[lower-alpha 2]}

The only cardinals who are assigned neither a titular church nor the title of a suburbicarian diocese are patriarchs of Eastern Catholic Churches: their respective patriarchates are considered to be their titles.^{[3][8][lower-alpha 3]}

As of 15 April 2024,^[update] there are 246 extant titular churches, 175 of which are titles and 71 of which are deaconries, and 7 suburbicarian dioceses. Currently, 16 titular churches (9 titles and 7 deaconries) and one title of a suburbicarian diocese are vacant. The tables below also indicate the 58 titular churches (45 titles and 13 deaconries) that are designated as basilicas.

As of 15 April 2024,^[update] there are 175 titles, 9 of which are vacant.

As of 15 March 2024,^[update] there are 71 deaconries, 7 of which are vacant.

As many as six cardinal bishops may be assigned titles not to a titular church or deaconry but instead to suffragan dioceses known as suburbicarian dioceses. These are dioceses located within the ecclesiastical province of the Diocese of Rome. Suburbicarian dioceses are not titular churches, but serve a similar function as honorary assignments that signifying the cardinals' relationship with the pope.^[272]

Since 1914, the title of a seventh suburbicarian diocese, that of Ostia, has been assigned ex officio to the dean of the College of Cardinals, in addition to that of his first suburbicarian diocese.^[3][273]

As of 27 May 2022,^[update] one title of a suburbicarian diocese is vacant.

• List of current cardinals
• Churches of Rome
• National churches in Rome