Precausa (Latin: Præcausa) was an ancient civitas of the Roman province of Byzacena in North Africa. Its exact location remains unknown but it was in the present Sahel region of Tunisia. Precausa was also the seat of an ancient diocese. Only one bishop of Precause is known from antiquity, Adeodato, who attended the Synod of Carthage (484) called by the Vandal king Huneric, after which Adeodato was exiled.