Giovanni Battista Vaccarini (3 February 1702 – 11 March 1768) was an Italian architect, notable for his work in the Sicilian Baroque style in his homeland during the period of massive rebuilding following the earthquake of 1693. Many of his principal works can be found in the area in and around Catania.
Vaccarini was born in Palermo. During the 1720s, he studied architecture in Rome, with the support of Cardinal Pietro Ottoboni, the great patron of Corelli. Vaccarini was mostly interested on combining the styles of Borromini and Bernini. This was an eclectic fusion of architectural principles that was common at the end of the 17th century, producing such notable buildings as Giovan Antonio de' Rossi's Palazzo Altieri, and Palazzo Asti-Bonaparte.
Vaccarini returned to Sicily around 1730. His work seems then to have been influenced by the school of architecture of Alessandro Specchi, Francesco de Sanctis and Filippo Raguzzini, who tended to reject the classicising of buildings in favour of a much more flamboyant style. Both Specchi and de Sanctis were closely involved with the design of grand exterior staircases, common to Italian buildings with a second-story piano nobile, and the climate completely negating the requirement for an internal entrance hall on the ground floor in order to provide quick easy access. De Sanctis had taken this feature one step further in 1723 with his design for the Spanish steps in Rome. This grand staircase approach to a building was to be invaluable in Sicily, not only for the practical reasons of entering the piano nobile, but also for the creation of a grand approach to churches and cathedrals, where the topography of the site permits such a feature.