St. Catherine's, church of the Sinaite monastery of the same name, lies to the northeast of St. Minas' Cathedral. Built in the Second Byzantine period, from the 15th to the 17th century it was a centre of cultural and intellectual activity, with an income sufficient to support a large monastic community. Under Ottoman rule it was converted into the Zulfikar Ali Pasha Mosque.

St. Catherine's is a basilica with transverse nave, the north end of which is domed and houses the chapel of the Ten Saints (Agioi Deka).