John Anthony McCarthy KC GCPO KCSG (born 20 October 1947) was the Australian Ambassador to the Holy See from 2012 to 2016, following the appointment of Bob Carr as foreign minister.

He has also acted as senior counsel for the national president of the St Vincent de Paul Society in Australia.

[10] McCarthy has appeared in cases in the High Court on native title, trade practices and electoral matters.

Other offices in which McCarthy has served include Pro-Chancellor University of Sydney (2005–10),[12] President of the St Thomas More Society – the Guild of Catholic Lawyers (1993-05),[13] Board Member of St Margaret's Hospital, Sydney (1997–99), and Australian Board member of international Catholic charity Aid to the Church in Need (1994–present).

In 2006, McCarthy received a Papal Knighthood, being appointed Knight Commander of the Order of St Gregory the Great by the Holy See for services to the Catholic Church and the wider Australian community.

[16] McCarthy discussed the position with The Catholic Weekly: "It is always a privilege and an honour to be called on to represent your country.

I am thankful to our Government for the opportunity to represent Australia in this important role in this great place, and to be able to go with Christine to the Eternal City and to have the occasion, opportunity and the presence of the Holy Father (i.e., the Pope) to put Australia’s case and to represent my country in that way.

"[17] Taking up his posting in August 2012,[18] McCarthy presented his diplomatic credentials to Pope Benedict XVI on 5 November 2012.

[21] Christine McCarthy DSS[22] was an accompished musician, concert pianist, accompanist and composer, the National Convenor of the Society for Eucharistic Adoration, served on the Liturgical Commission for the Archdiocese of Sydney, and wrote and lectured extensively on Catholic themes.

[24] Their second son, Father James McCarthy, is a priest of the Archdiocese of Sydney; he studied for the priesthood in Rome and was ordained in 2009.