The patron saint of Alatri is Pope Saint Sixtus I: the popular devotions dedicated to him extend throughout the year and reach their peak on the Wednesday after Easter, when the Feast of Saint Sixtus is celebrated.
On 11 January, celebrated in dialect as «San Sisto Ginnàr'», the anniversary of the arrival in Alatri of the patron saint's relics is instead commemorated. Among the town's other traditions is the Good Friday Procession, a historical-religious re-enactment of Scripture, the Way of the Cross and Golgotha, as well as the Palio di Alatri, a historic town competition.