The patron of Castro dei Volsci is Saint Oliva, celebrated on 3 June in the Church of Sant'Oliva.
The townspeople's devotion to their patron dates back to the early Middle Ages; the saint was formerly venerated on 15 January, before the feast moved to today's date. The oldest wooden statue was replaced in 1912 by the current one, carried in procession on a gilded metal throne. The town also holds the Church of San Nicola, with notable traces of frescoes.
