The present Cathedral of St. Mary, inside the Citadel, was erected soon after the earthquake of 1693, which had destroyed the previous medieval church. It was designed by the local architect . Lorenzo Gafa' who was also responsible for the Cathedral of Mdina which had suffered the same fate in the earthquake. The building was completed and consecrated in 1716.

Like Mdina, the Gozo Cathedral follows the baroque style of the period, with the Jesuit -type facade common in all catholic countries at that time. A notable variation from Mdina is that owing to shortage of funds, this Cathedral was left without a dome. However, something had to be done and, in 1732, a trompe I'oefi or illusion of a dome was painted on the flat ceiling of the drum at the intersection of transepts and nave. This remarkable false dome, the work of Antonio Manuele of Messina, is a big attraction to those visiting the Cathedral.

St. Mary's was made into a Collegiate Church in 1623. At that time it was the principal church of Gozo. Nowadays, Rabat (Victoria) has another parish - that of St. George. However, St. Mary's Cathedral, apart from being a parish church, remains the head of all churches in the island.

Until 1864, Gozo was a dependency of the See of Malta; but in that year, the little island became an independent Diocese. Since then it has had its own bishops, and the Collegiate Church became the Cathedral of the Assumption (St. Mary).

Inside the Cathedral one can appreciate the fine statue of Our Lady on a solid silver pedestal. The statue is carried in procession on Assumption Day, the 15th of August. That is a day of great festivity in Rabat, and the principal date in Gozo's ecclesiastical calendar. Another important event at St. Mary's Cathedral is the Good Friday procession characterised by biblical costumes and statues representing the Passion of Our Lord.

The nave and aisles of the Cathedral are paved with coloured marble tomb-slabs of deceased members of the Cathedral Chapter. Works of art include the vault and the altar paintings by eminent local artists, an alabaster font dating from 1742, and the monuments of bishops and leading prelates.