The 1693 Catania earthquake, which caused 60000 deaths in eastern Sicily and generated a 5--10 m high tsunami, is investigated. GPS data indicate ESE-WNW convergence in the Calabrian arc at 4--5 mm/yr. New high-resolution seismic data image active compression at the toe of the accretionary wedge. The lack of instrumentally recorded thrust earthquakes suggests the presence of a locked subduction fault plane. Thermal modeling is applied to calculate the limits of the seismogenic zone. Tsunami modeling is performed to test the hypothesis that the 1693 earthquake occurred on the subduction fault plane (160 ¿ 120 km in size) with 2 m of mean co-seismic slip. This source successfully reproduces historical observations with regard to polarity and predicts 1--3 m high amplitudes. It is likely that only the SW segment of the subduction fault plane ruptured in 1693 and 1169, implying a recurrence interval of roughly 500 years for similar events.