Carlo Alberto Guidoboni Cavalchini (26 July 1683 – 7 March 1774) was an Italian Cardinal.
Considered papabile in the Papal conclave, 1758, he was vetoed by Louis XV of France under the jus exclusivae.
A lawyer by education, he became titular archbishop of Filippi in 1728, and was created Cardinal in 1743.
He became bishop of Albano in 1759 and bishop of Ostia in 1763.