Girolamo Grimaldi (1674 – 18 November 1733) was a cardinal who worked in the diplomatic service of the Holy See and in the government of the Papal States.
Baptized in Genoa on 15 November 1674, Grimaldi graduated from the University of Avignon on 26 June 1705 with a law degree.
Four years later, he was ordained as a Roman Catholic priest, on 7 April 1709, and was appointed Internuncio to Brussels.
On 5 October 1712 he was appointed titular Archbishop of Edessa in Osrhoëne and sent as Nuncio to Poland.
In 1720 he became Nuncio to Austria Ten years later, he was created a cardinal in the consistory of 2 October 1730 and appointed the papal legate for Bologna.