The patron of Simaxis is Pope Saint Symmachus, celebrated on 19 July in the Church of San Simaco Papa, with religious celebrations. A committee organizes the patronal feast every year, lasting several days.
The town is also known for its retro-style Carnival, usually held on the Saturday of Shrove Tuesday week and known as Sa Coja de tziu Damus, «uncle Damu's wedding». The town holds the Church of San Nicolò di Mira and Piazza Madre Teresa di Calcutta.
