Cardinal Keith Michael Patrick O’Brien, Archbishop emeritus of Saint Andrews and Edinburgh (Scotland, GB), was born on 17 March 1938 in Ballycastle, County Antrim, Northern Ireland. 

He was ordained a priest on 3 April 1965. He obtained a bachelor of science degree in chemistry and mathematics from the University of Edinburgh and a diploma in education.

Cardinal O’Brien served as assistant parish priest and as chaplain of St Columba Secondary School in Cowdenbeath, where he taught math. He was spiritual director of St Andrew's College in Drygrange and rector of St Mary’ College, Blairs. 

On 5 August 1985 he was ordained Archbishop of Saint Andrews and Edinburgh. In 1991, Archbishop O’Brien was awarded the Equestrian Order of the Holy Sepulchre of Jerusalem: Knight Commander with star. From 1996-1999 he served as Apostolic Administrator of the Diocese of Argyll and The Isles.

Since March 2002 until 2012, Cardinal O’Brien has been President of the Bishops’ Conference of Scotland.

Archbishop emeritus of Saint Andrews and Edinburgh, 18 February 2013.

Cardinal Keith O’Brian did not participate in the conclave of March 2013. In May 2013, in agreement with Pope Francis, he left Scotland for a period of spiritual, prayer and penance renewal.

In March 2015, the Holy Father Francis has accepted the resignation of the rights and privileges of a Cardinal, expressed in canons 349, 353 and 356 of the Code of Canon Law, presented by  Cardinal Keith Michael Patrick O’Brien, Archbishop Emeritus of Saint Andrews and Edinburgh, after a long period of prayer.

He participated in the conclave of April 2005, which elected Pope Benedict XVI.

Created and proclaimed Cardinal by St. John Paul II in the Consistory of 21 October 2003, of the Title of Ss. Gioacchino e Anna al Tuscolano (Sts. Joachim and Anne al Tuscolano).