Santa Giusta Cathedral, now a minor basilica (Italian: Basilica di Santa Giusta) is the former cathedral of the abolished Diocese of Santa Giusta, in Santa Giusta, province of Oristano, Sardinia, Italy. The dedication is to Saint Justa of Cagliari who, according to the tradition, was martyred here at the time of the Roman emperor Diocletian, with her companions Saints Justina and Aenidina.