The patron of Casamarciano is Pope Saint Clement, celebrated on 23 November in the Church of San Clemente.
Since 2011, every September, the «Città di Casamarciano» national theatre festival has been held: the first edition was won by the Piccolo Teatro di Salerno, with actor Carlo Buccirosso as guest of honor. Since 2012, after the festival, further evenings are held on the far side of the Castello Badiale, in an event called «Settembre al Belvedere». The town also holds the Church of Santa Maria del Plesco.
