The Archdiocese of Oristano is a Latin archdiocese of the Catholic Church in Sardinia, Italy. It was created in the eleventh century. Its only suffragan is the Diocese of Ales-Terralba. Since 2019 the Archbishop of Oristano has been Roberto Carboni.

Archbishops

It would appear that a process has begun to permanently unite the diocese of Ales-Terralba and the archdiocese of Oristano. The Bishop of Ales-Terralba, Roberto Carboni, O.F.M. Conv., was promoted on 4 May 2019 to be Archbishop of Oristano and on the same date was appointed Apostolic Administrator of his former diocese of Ales-Terralba. However, on 3 July 2021, without losing his position as Archbishop of Oristano, he was reappointed Bishop of Ales-Terralba. The announcement specifies that this act unifies the two dioceses in persona Episcopi ('in the person of the Bishop').