Edward Idris Cassidy AC (5 July 1924 – 10 April 2021) was an Australian prelate of the Catholic Church who was president of the Pontifical Council for Promoting Christian Unity from 1989 to 2001.

Due to financial difficulties after his grandfather died, he left school to support his grandmother in 1939 and worked at the New South Wales Department of Road Transport as a junior clerk.

In 1942, he presented his case for entering the seminary directly to Archbishop Norman Gilroy of Sydney, who accepted his arguments.

He completed his education studying at the Pontifical Lateran University in Rome, where he obtained a doctorate in canon law in July 1955 with a dissertation on the history and juridical nature of apostolic delegations, and at the Pontifical Ecclesiastical Academy, also in Rome, from October 1953, where he obtained a diploma in diplomatic studies.

[1] Reflecting on his involvement, Cassidy joked that signing it would be the one thing he could confidently cite on his behalf on judgement day.

[9] When he retired in 2001, he returned to his native Australia, where he substituted for local priests on occasion and served as chaplain to the Italian-speaking community of Newcastle.

[11] In 1990, Cassidy was appointed a Companion of the Order of Australia (AC) in "recognition of service to the [sic] religion and to international affairs".

[12] In 2006, the LDS Church in Australia presented Cassidy with an award for his efforts to bring better understanding to the people of the world.