[1] Nolan completed his studies for ordination at the Pontifical Scots College, Rome, from 1971 to 1978, earning a license in sacred theology from the Gregorian University in June 1978.

While parish priest at Our Lady of Lourdes, East Kilbride, from 1994 to 2014 he held several other assignments, including judge of the National Ecclesisatical Tribunal in Scotland, dean of his zone, head of permanent formation of the clergy of Motherwell, and a member and vice-president of the Presbyteral Council.

[3] In 2013, Nolan was appointed administrator of St John Ogilvie Parish in Blantyre when its pastor, Matthew Despard, was suspended during a canonical investigation.

[7] At the time of his appointment, the Galloway diocese had "a troubled history of rebel priests" and Nolan's predecessor had been incapacitated by poor health for several years.

[11] In 2021, he established a Scotland-wide Care of Creation Office to reflect the priorities of Pope Francis' encyclical Laudato Si' and anticipating the 2021 United Nations Climate Change Conference in Glasgow in November.

[13] He is the president of Justice and Peace Scotland, a national body that advocates on a variety of social issues from climate change to nuclear weapons.