Born in Melbourne, he was educated at the selective Melbourne High School. He holds a Bachelor of Arts and a Bachelor of Laws from the University of Melbourne, a Master's of Literature from the University of New England, and a teaching diploma and semikhah (rabbinic diploma) from Jews' College (now the London School of Jewish Studies). He is a Doctor of Laws honoris causa from the University of New South Wales, a Doctor of the University of the Australian Catholic University, and Honorary Fellow of the University of Sydney. He has received a Distinguished Alumni award from the University of New England.
Apple served London congregations at Bayswater and Hampstead between 1960 and 1972 before returning to Australia to take up the role of senior rabbi at the Great Synagogue (Sydney).
In Sydney he also served as a dayan and registrar for the Sydney Beth Din.
Interfaith dialogue has been a lifetime interest of Apple and one which he pursued in Sydney. He is a patron and a former joint president and chairman of the Australian Council of Christians and Jews. He is also a life member and former chairman of the NSW Council, founded the Christian-Jewish Luncheon Club in Sydney, and has been a leader in dialogue with Islam.
Apple is an Officer of the Order of Australia for his services to the community, as well as holding the Queen's Silver Jubilee Medal and the Centenary of Federation Medal.
Apple was an Australian Army Reserve chaplain for 15 years and from 1988-2006 senior rabbi to the Australian Defence Force. He also served for two terms as chairman of the Religious Advisory Committee to the Services, the first Jewish representative to hold this office. He was awarded the Reserve Force Decoration and the Australian Defence Medal. He was also a chaplain to the NSW Police.
Apple is prominent in Freemasonry, being a Past Deputy Grand Master, Past Junior Grand Warden and Past Grand Chaplain of the United Grand Lodge of New South Wales and the Australian Capital Territory.
Apple has lived in Israel since 2006.
Apple has written a number of books, including :New Testament People: A Rabbi’s Notes. Bloomington: AuthorHouse. 2016. pp. 236 p. ISBN 978-1-52462-994-6.
Enemies and Obsessions: More Memories and Musings. Bloomington: AuthorHouse. 2014. pp. 138 p. ISBN 978-1-49699-223-9.
Eighty Days and Eighty Nights: Wise Words for Everyday. Bloomington: iUniverse. 2012. pp. 64 p. ISBN 978-1-47594-654-3.
Education by Degrees: Masonic Notes. Bloomington: AuthorHouse. 2012. pp. 86 p. ISBN 978-1-4772-2334-5.
Let's Ask the Rabbi. London: AuthorHouse. 2011. pp. 316 p. ISBN 978-1-4567-7269-7.
Freemasonry: Studies, Speeches and Sensibilities. Sydney: The Museum of Freemasonry. 2010. pp. 181 p. ISBN 978-0-9807584-0-5.
Episodes and Eccentrics: More tales of The Great Synagogue. Sydney: The Great Synagogue. 2010. pp. 79 p. ISBN 978-0-9592404-3-6.
To Be Continued: Memoirs and Musings. Sydney: Mandelbaum Publishing. 2010. pp. 222 p. ISBN 978-0-9804722-1-9.
The Great Synagogue: A History of Sydney's Big Shule. Sydney: UNSW Press. 2008. pp. 342 p. ISBN 978-0-86840-927-6.
The Jewish Way: Jews and Judaism in Australia. Sydney: The Great Synagogue. 2002. pp. 72 p. ISBN 0-9592404-2-X.
The Jews. West Melbourne, Vic.: Thomas Nelson Australia. 1981. pp. 112 p. ISBN 0-17-005566-3.
The Hampstead Synagogue 1892-1967. London: Mitchell Vallentine. 1967. pp. 120 p.
He has also published numerous articles on Jews, Jewish history, the Jews in Australia, and various Jewish and interfaith themes. He is the author of "OzTorah", a weekly e-mail service and website presenting insights into the Torah reading, an Ask the Rabbi forum, and articles on Freemasonry, interfaith issues, British Jewish history, and the Australian Jewish community and its history. The OzTorah archives are available on his website at http://www.oztorah.com