The patron saint of Ferentino is Saint Ambrose the martyr, celebrated on 1 May.
The town's co-patron is Saint Celestine, whose heart remains in Ferentino, kept at the monastery of the Poor Clare nuns: in his honour, since 2002, the traditional palio, or ring joust, has been held every year. The town also holds the church of Santa Maria Maggiore, that of Sant'Ippolito and the Roman Market.