The Archdiocese of Oristano (Latin: Archidioecesis Arborensis) is a Latin archdiocese of the Catholic Church in Sardinia, Italy.

It would appear that a process has begun to permanently unite the diocese of Ales-Terralba and the archdiocese of Oristano.

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.

[1] 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').