Lorenzo Gafa (1639-1702), a Maltese architect, is the person to be accredited for the architecture of the Cathedral. The cathedral has a particularly striking facade, striking not through intricacy, but its boldness found in simplicity. With the use of Corinthian and Composite orders, one can simply describe the building as being robust in appearance. Though there are numerous areas of blank masonry, the central section of the facade is set further than the others, giving a three dimensional aspect to the otherwise monotonous style. A triangular pediment holding a two armed cross sits atop this facade, along with the dome, one of the most spectacular on the island, and a sight to be marvelled at from afar. Giuseppe Darmanin, a leading marble sculptor at the time, created three shields which crown the main entrance into the cathedral. These three shields depict the coat of arms of the city of Mdina, the Bishop David Cocco Palmieri, and the Grand Master Ramon Perellos.
As a product of the bottega of Mattia Preti, Gio Battista Caloritti designed the chestnut door found below these shields. Giuseppe Stefanin modelled two wonderfully intricate statues of St. Paul and St. Peter, which were then cast by Luca Menville, of the well known Menville family. Between the three shields and the door, rests a coloured shield which depicts the coat of arms of the serving Archbishop, while acting as a centre to the whole facade. Six bells used to be housed in the belfries, the eldest of which was cast in Venice back in 1370 by Magister Victor et Nicolas Frater, which may be currently found in the Museum. In 1699, six brave slaves earned 11 scudi for their troubles, as they hazardously hoisted the bells into position. The clocks on the facade were created by the famous Maltese clock-maker Michelangelo Sapiano in 1888.