The main Catholic church on Santorini is the Cathedral of Saint John the Baptist, located in Fira.
Getting there: The church is located near the main square and overlooks the ocean where many cruise ships and ferries come and go. You may want to consider booking a private tour through Tours by Locals. There are daily Masses (in Greek) as well as Masses on Saturdays and Sundays.

Mass in the Cathedral is at 10:00 a.m. on Sundays from June through the end of September as well as 7:00 p.m. on Saturdays. We believe these are English-language Masses but will try to find out for sure. Daily Mass is at 8:00 a.m. and is held in the Monastery of the Dominican Sisters next to the Church. We are not aware of any website for the Cathedral itself, but click here for a website for the Diocese of Santorini. Soutcr :https://thecatholictravelguide.com/