The patron of Ardenno is Saint Lawrence, celebrated on 10 August.
Numerous popular religious celebrations, mostly concentrated in summer, animate the town's hamlets: Saint Joseph is celebrated on 1 May in the hamlet of Pilasco, Saint Gotthard on the first Sunday of May at the shrine in the Pioda locality, and the Nativity of Saint John the Baptist on 24 June at the Val Mala church. The town also holds the Parish Church of Santa Maria Assunta and the San Rocco chapel.