The patron of Olzai is Saint John the Baptist, celebrated on 24 June; the municipality holds the church of San Giovanni Battista.
The calendar of popular feasts and traditions includes «Terra Ruvia», between 31 December and 1 January; the bonfire of Saint Anthony the Abbot, on 16 January; the feast of Saint Anastasius, on 22 January; Carnival, with the Pentolaccia on the Sunday after Ash Wednesday; the feast of the Angel, on the second Sunday of May; Saint Isidore, on the third Sunday of May; Saints Peter and Paul, on 29 June; Saint Barbara, on 26 August; the prickly-pear sagra, in the last days of September; and Cortes Apertas, in mid-November.
