Guido Calcagnini (25 September 1725 in Ferrara – 17 August 1807 in Osimo) was an Italian cardinal and titular archbishop in the Roman Catholic Church.

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He was born into a noble family, as the son of the count palatine Cesare Calcagnini, marquess of Fusignano and a relation of cardinal Carlo Leopoldo Calcagnini. He studied at the Collegio dei Nobili di San Carlo at Modena and then at the Sapienza in Rome – at the latter, on 15 May 1747, he gained a doctorate in theology and in utroque iure.

He entered the papal court as private chamberlain to the pope in 1746.