The patron of Ulassai is Sant'Antioco, celebrated fifteen days after Easter.
The municipality also holds the Grotta di Su Marmuri and the Nuraghe Pranu. On the morning of 1 November, All Saints' Day, children knock from door to door with the classic cloth sack on their shoulders asking for gifts and sweets for «is Animas» (the souls), in a tradition closely resembling Halloween as celebrated overseas.
