The patron of Gromo is San Giacomo apostolo, celebrated on 25 July; the village holds the Chiesa di San Giacomo e San Vincenzo.
On the day of the feast the statue of San Giacomo is carried in procession to the parish church, where a solemn mass is celebrated; a dinner at the oratory follows, with gnocchi in colla, a dish typical of the place. The municipality also holds the Cappella di San Benedetto, the Chiesa della Santissima Trinità, the Chiesa della Visitazione di Maria Santissima, the Chiesa di San Bernardino and the Museo delle armi bianche e delle pergamene.
