The patron of Castel Guelfo di Bologna is Saint Agnes, celebrated on 21 January.
The town has traditions marked by the seasons: the last weekend of June brings the Sagra del vino e della ciambella (wine and ring-cake fair), the second Sunday of May the Medieval Feast, and every five years, in the last week of September, the Festa bella, a religious event that draws the faithful around the town's miraculous Crucifix, carried in solemn procession while the centre is lit up and decorated for the feast. The town also holds the Torre di Castel Guelfo and the Shrine of the Beata Vergine di Poggio Piccolo.
