Chiesa di San Giovanni Battista, Roman Catholic church in Marsala, Italy

The Chiesa di San Giovanni Battista, also called San Giovanni al Boeo, is a church of simple architectural style built in 1555 by the Jesuits on Capo Boeo near the coast. It stands within the archaeological area of Capo Boeo and belongs to the parish of San Tommaso di Canterbury. Beneath it lies the Grotta della Sibilla, a rock-cut complex at -4.80 m with a circular central room covered by a low masonry dome and a square baptismal basin fed by a spring.

The church was built in 1555 by the Jesuits on Capo Boeo, near the coast. It was not the first church on the site: with Santa Maria della Grotta it formed part of the ancient abbey of the Basilian Fathers. Since 1788 San Giovanni Battista has been co-patron of Marsala, having previously been its patron saint.

The church is also called San Giovanni al Boeo and belongs to the parish of San Tommaso di Canterbury, the mother church of Marsala. Since 1788 John the Baptist has been co-patron of the city, formerly its patron. On 24 June, his feast, Masses are celebrated hourly by the archpriest and parish priests, followed by a procession and fireworks.

The church stays closed most of the year and opens on 24 June for the feast of Saint John the Baptist, with Masses celebrated hourly and the last one in the afternoon followed by a procession. It can also be opened on request for weddings and baptisms. Entry to the church and the Grotta della Sibilla is free, and the building stands inside the archaeological area of Capo Boeo.

The church stands within the archaeological area of Capo Boeo, a short walk from the sea. Beneath it, at a depth of 4.80 metres, lies the Grotta della Sibilla, reached through a low masonry dome with a skylight set into the church floor. A spring still feeds the square basin where early Christians were baptised.