The pre-Reformation Diocese of Galloway, founded by Ninian in the fifth century, had broken allegiance with Rome in 1560, and disappeared in 1689 in the (official) Church of Scotland but continued in the Episcopal Church of Scotland.

The diocese was re-established by the Catholic Church on 4 March 1878, with its cathedral in Dumfries and its territory covering the sparse and rural counties of Dumfriesshire, Kirkcudbrightshire, Wigtownshire and parts of Ayrshire.

In response to this development Bishop McGee moved his residence from Dumfries to Ayr, and following a catastrophic fire at St Andrew's Cathedral in May 1962, it was decided that the Good Shepherd Church, Ayr should also become the diocesan cathedral.

The eighth bishop of the diocese was William Nolan, since 2022 the Archbishop of Glasgow.

(The following list is included in, but is not the only part of, post-Reformation bishops in the above-mentioned main article.)