Although dedicated to St. Catherine, Zejtun’s first parish church is commonly known as St. Gregory’s because of the annual pilgrimage to this place. It is one of Malta’s finest old churches. Very little remains of the original rectangular church built before 1436, the time when Żejtun became a separate parish, apart from Mdina and Vittoriosa.

This present church was constructed on and around the site occupied by the old medieval church, so that the present edifice dates from the sixteenth century. For about three centuries this building served as the parish church for all the south-east of Malta. One cannot fail to admire the Gothic and Romanesque styles of architecture. The primitive dome is the most ancient example of Maltese cupolas still standing. Of particular interest is also the orientation of the south-east transept of the church which is aligned with the bays of Marsxlokk, St.Thomas and Marsakala, since the church also doubled as a watch tower. The church occupies the highest point overlooking the harbours in the South, favourite landing place for barbery corsains.

Near the St. Gregory's Church there is the statue of Pope St. Gregory the Great and the three cemeteries of Żejtun, Saint Rocco (the oldest one), St. Gregory and St. Catherine's.