The patron saint of San Giovanni in Marignano is Saint John the Baptist, celebrated on 24 June; the other patron, Saint Lucy, is celebrated on 13 December.
Through the streets of the historic centre, from the summer solstice on 21 June to the patronal feast, the Night of the Witches is held, an event recalling popular traditions and the rites of Saint John's Eve. The town also holds the Church of San Pietro Apostolo and the Valconca Natural History Study Centre.