Roman Catholic Diocese of Argyll and the Isles

The Diocese of Argyll and the Isles (Latin: Dioecesis Ergadiensis et Insularum ) is a diocese located in Scotland, the Roman Catholic Church. It was on March 5, 1878 as part of the restructuring of the Catholic Church in Scotland by Pope Leo XIII. built with the Zirkumskriptionsbulle Ex supremo Apostolatus apice and is based in Oban. Today it consists of three deaneries and is rural. The bishops of the diocese are members of the Scottish Bishops' Conference.

The diocese united the territory of the medieval dioceses Argyll and Sodor & Man (or the Isles ). The name affix the Isles refers to the Hebrides.

There is also a diocese of the same name of the Scottish Episcopal Church, which is part of the Anglican Church.