Bishop John was born on 19th December 1964 in Glasgow. He studied at the University of Glasgow (LL.B) and the Gregorian University, Rome (S.T.B., Ph.L), before studying at the Pontifical Scots College, Rome. He was ordained a priest on 9th July 1995 in St Gregory's, Wyndford, by Cardinal Thomas Winning, Archbishop of Glasgow.
He served as Chaplain to the University of Glasgow (2000–2014), Parish Priest of St Patrick's, Anderston (2013–2014), and Vocations Director of the Archdiocese of Glasgow. He was nominated as Bishop of Paisley by Pope Francis on 8th February 2014, and was ordained the fifth Bishop of Paisley on 19th March 2014 by Archbishop Philip Tartaglia.
“Suscepit servum, recordatus misericordiae” — “He protects his servant, remembering his mercy”, Bishop Keenan's episcopal motto, taken from the Magnificat.
Homily of Rt. Rev. Mgr. Thomas J. Provost Monaghan, on the occasion of the Presentation of the Coat of Arms to Bishop Keenan.