Mark O'Toole (born 22 June 1963) is a British Catholic prelate who has served as Archbishop of Cardiff-Menevia since its formation on 12 September 2024.

[1] He commenced his studies for the priesthood at Allen Hall Seminary in Chelsea and was ordained a priest on 9 June 1990 by Basil Hume for the Archdiocese of Westminster at the Church of St Ignatius, Stamford Hill, London.

[1] Between 2002 and 2008 he served as the private secretary to Cormac Murphy-O'Connor before his appointment as the rector of Allen Hall Seminary in September 2008.

[6] On 27 April 2022, Pope Francis appointed O'Toole Archbishop of Cardiff, succeeding George Stack.

His installation took place in Cardiff Cathedral on 20 June 2022, the feast day of Welsh martyrs Saints Julius and Aaron.