On Piazza Lionardo Vigo, a short walk south of Piazza Duomo, the Collegiate Basilica of San Sebastiano is considered the finest Baroque church in Acireale — which is saying something in a town full of Baroque churches. The facade is a textbook example of Sicilian Baroque excess: voluted columns, elaborate stonework, statues in every niche, and a balustrade running along the top adorned with yet more statues.
The church dates from the fifteenth century but was rebuilt completely after the 1693 earthquake in the style you see now. The interior is relatively restrained by comparison with the facade, though the painted ceiling panels and the silver reliquary of San Sebastiano (patron saint of Acireale) are worth examining.