The Apostolic Datary (Latin: Dataria Apostolica) was one of the 5 Ufficii di Curia ("Offices of the Curia") in the Roman Curia of the Roman Catholic Church. It was instituted no later than the AD fourteenth century. Bl. Pope Paul VI abrogated it in 1967.
According to the De officio et jurisdictione datarii necnon de stylo Datariae of Amydenus and other authorities, the Dataria Apostolica was of very ancient origin, but the previous transaction by other offices of the business that was gradually assigned to it contradicts these authorities. The Dataria was principally entrusted with concession of matrimonial dispensations of external jurisdiction and with collation, i. e., conferral, of benefices and rescripts that were reserved to the Apostolic See. To this double faculty was later added the third of granting many other indults and favors. Until the pontificate of Pope Pius IV, matrimonial dispensations were granted through the Apostolic Penitentiaria. Regarding the authority of collation of reserved benefices, it could not have been granted in ancient times because the institution of those reservations is comparatively recent: although some vestige of the reservations is found prior to the twelfth century, the custom was not frequent before Pope Innocent II, and the reservation of benefices was instituted as a general rule (De pract. et dignit., 3, 4, c. 2 (6°)) only from the pontificate of Pope Clement IV. While the office certainly existed in the fourteenth century, and as an independent one, the date of its institution is unknown.
The Dataria consisted first of a cardinal as its principal who was titled the "Pro-Datary" ("Prodatarius") until Sapienti Consilio of Pope St. Pius X, and thereafter was titled "Datarius" ("Datary"). There was formerly as much discussion of the title of "pro-datary" as of that of "vice chancellor" of the Apostolic Chancery: some contend that the title is derived from the fact that the office dated the rescripts of the Supreme Pontiff, while others that it is derived from the right to grant (dare) the indults and rescripts for which petition was made to the Supreme Pontiff. It is certain that, on account of these faculties, the Datary enjoyed great prestige during the flourishing of the office, when he was denominated the "Oculus Papae" ("Eye of the Pope"). After the Cardinal Datary came the "Subdatary" ("Subdatarius"), a prelate of the Roman Curia who assisted the Datary and assumed almost all of the faculties of the Datary as his substitute on occasion. After the Subdatary came a number of subordinate officials who, as De Luca stated, had enigmatical and sibyllic titles, e. g. the "Prefect of the Per Obitum", "Prefect of the Concessum", "Cashier of the Componenda", and "Officer of the Missis".