Pietro Marcellino Corradini (2 June 1658 - 8 February 1743) was an Italian Catholic prelate who served in various departments of the Roman Curia under several popes and founded the Collegine Sisters of the Holy Family as a response to the demand for religious instruction for girls.

In 1699 Pope Innocent XII appointed him a canon of the Basilica of Saint John Lateran despite the fact that he had not as yet been ordained to the priesthood.

In the same year Cardinal Leandro Colloredo appointed him as a canonist and auditor at the Apostolic Penitentiary, and this was confirmed by a papal bull on 19 August 1706.

He also successfully opposed the Emperor's attempt to impose a favorite, Hugh Francis von Fürstenberg, as bishop of Hildesheim without Clement XI's approval.

On 11 September 1726 he received authorization from the pope to hold his titular church "in commendam" and simultaneously the appointment of Cardinal-Priest of Santa Maria in Trastevere.

[1] At present, Corradini's religious congregation, now known as "Le Suore collegine della Sacra Famiglia" ("College Sisters of the Holy Family) has spread across the world and now operates in Albania, the United Kingdom, Mexico, Romania, Tanzania and in Kenya.