Pope Marcellus II (Italian: Marcello II; 6 May 1501 – 1 May 1555), born Marcello Cervini degli Spannocchi, was head of the Catholic Church and ruler of the Papal States from 10 April 1555 to his death, 22 days later.
Marcellus succeeded Pope Julius III. Before his accession as pope he had been Cardinal-Priest of Santa Croce in Gerusalemme. He is the most recent pope to choose to retain his birth name as his regnal name upon his accession, and the most recent pope to date with the regnal name "Marcellus".
Marcello Cervini's father, Ricardo Cervini, was a personal friend of Pope Clement VII. Cervini served in the household of Cardinal Alessandro Farnese. When Farnese became Pope Paul III, Cervini served as his secretary and was employed on a number of diplomatic missions.