The Roman Catholic Diocese of Suacia (Latin: Dioecesis Suacinensis, Albanian: Dioqeza e Shasit, Serbian: Svačka biskupija) was a bishopric with see in the town of Svač (Latinized as Suacia), which is today the village lying to the east of Ulcinj in Montenegro that is called in Serbian Шас, in Croat Šas and in Albanian Shas.