After nine years as a music producer at the Australian Broadcasting Corporation, from 1972 on the invitation of Dame Joan Hammond he became the music director of the Victoria State Opera in Melbourne, where he remained for 25 years. A further five years were spent as Principal Resident Conductor of Opera Australia. His teachers included Joseph Post, Nikolaus Harnoncourt, Sir Charles Mackerras, Sir Reginald Goodall and Wolfgang Wagner. He was born in Sydney.
Divall conducted many concerts, ballets and 151 operas, particularly works of the late baroque, Mozart, Handel, Gounod, Berlioz and Verdi. These included the complete operas of Claudio Monteverdi, Berlioz's Les Troyens and Richard Strauss' Elektra. He conducted Verdi's Don Carlos, the first opera to be staged in the State Theatre of the Victorian Arts Centre in 1984.
His repertoire included Lohengrin and Tannhäuser by Wagner. The most recent operas he directed were Donizetti's Maria Stuarda, Hasse's Antonio e Cleopatra, Bizet's Les pêcheurs de perles, and Puccini's final opera Turandot at Monash University.
As a musicologist he edited over 150 works of early Maltese composers especially from the period of the knights, including the complete sacred music and operas by Nicolas Isouard (1773–1818). He was editing the sacred music and operas of Girolamo Abos (1715–1760).
Four volumes in his editions of 24 works of Michel' Angelo Vella have been published by Lyrebird Press [Paris/Melbourne]. Divall was associated with several residential colleges of the University of Melbourne, first Queen's College (of which he was a fellow) and later Newman College (where he was a member of the SCR). In 2014, he was appointed an Honorary Research Fellow at the University of Divinity, Melbourne, and in September 2014 a Visiting Professor of Music at King's College, London.
For 45 years, Divall pioneered the study of, edited and published many volumes of early Australian music. He was the Chairman of the Marshall-Hall Trust, and was completing an edition of the complete works of the English baroque composer Michael Christian Festing, and the Complete Sacred Music of Girolamo Abos (1715–1760).  Divall worked in several fields at Monash, was a member of the committee for the construction of the new Sir Zelman Cowen School of Music, as well as assisting the staff and students at that school. In 2015 he was the co-producer of the ANZAC Commemorative CD Gallipoli – A Tribute, which was sponsored by the Ian Potter Foundation and Monash University.
- Complete works of Linger, 1971
- Symphonies, Cipriani Potter, Samuel Wesley, 1980
- Concerto for Violin and Orchestra, Op. 29 by C E Horsley (Melbourne: Lyrebird Press, 2008)
- Edited works by Gluck, Rameau, George Frideric Handel, Wesley, Bellini, Verdi, the Complete Sacred Music of Nicolo Isouard (1773–1818), and the Complete Works of Michael Christian Festing (1705–1752).
- Lohengrin – Alberto Remedios, Elsa – Karen Bureau, Ortrud – Nance Grant, Telramund – Geoffrey Chard, King Henry – Noel Mangin, Herald – David Brennan; Melbourne Symphony Orchestra Conductor Richard Divall. Victoria State Opera. Australian Radio Broadcast November 1985. CD91241
- Margreta Elkins (Cassandre), Robert Allman (Chorèbe), Alberto Remedios (Enée), Suzanne Johnston (Ascagne), Lauris Elms (Didon), Heather Begg (Anna), Richard Greager (Iopas/Helenus), Noel Mangin (Priam/Narbal), John Wood (Panthée); Victoria State Opera Melbourne Symphony Orchestra, Melbourne Chorale & Victoria State Opera Chorus, Richard Divall
- Elizabeth I – Nance Grant, Mary Stuart – June Bronhill, Earl of Leicester – David Parker, Lord Talbot – John Bolton-Wood, Lord Cecil – Barry Clark, Ann Kennedy – Janet Dawson, Victorian State Opera, Victorian State Opera Orchestra and Chorus. Melbourne 24 July 1976 Conductor::Richard Divall
- Leanne Kennealy – Julian Gavin; Conducted by Richard Divall – Sydney 1999
- Joan Sutherland – Sally-Anne Russell – Wendy Dixon – Elizabeth Campbell – Glen Winslade – Stephen Bennett; Conducted by Richard Divall. Australian Opera, Australian Opera Chorus. Sydney 1987
Divall was awarded honorary degrees from Monash and Australian Catholic University and a PhD in Theology by the University of Divinity [Catholic Theological College] in church history and 18th century Maltese sacred music. He was an Officer of the Order of Australia (2009), an Officer of the Order of the British Empire (1981) and was awarded a Spanish knighthood in 2008.
He was a Fellow of Queen's College, and was on the SCR of Newman College at the University of Melbourne. He was a Knight of Malta in solemn religious profession and was active in hospitaller and charitable works in that order.
- Frà Professor Richard Divall AO, OBE
- Officer of the Order of the British Empire, OBE (1981)
- Officer of The Order of Australia, AO (2009).
- Officer of the Most Venerable Order of St John, OStJ (2012).
- Fellow, Royal Numismatic Society (1985).
- Fellow, Royal Asiatic Society (1985).
- Fellow, Queen's College, University of Melbourne in 1987.
- D. Lett (Hon Causa) Monash (1992)
- Doc. Univ. (ACU) 2005)
- PhD. UD. (2014)
- Dame Joan Hammond Award in 1988
- Bayreuth Prize in 1990
- Cavaliere di Giustizia (Order of Malta), Cavaliere di San Giorgio (Spain)
- Commendatore al Merito Melitense, DLett (Hon Mon) in 1989, for historical research
- FRAS, FRNS.
- Frà Professor Richard Divall AO OBE D Lett (Hon Mon) Doc Univ (ACU) PhD (UD) FRNS FRAS
- McPherson, Angus (16 January 2017). "Richard Divall has died". Limelight. Retrieved 30 January 2017.
- "Victoria State Opera: Faust 1981". Victoriastateopera.wordpress.com. Retrieved 15 January 2017.
- "Victoria State Opera – Don Carlo 1984". Victoriastateopera.wordpress.com. 18 June 2013. Retrieved 15 January 2017.
- "Divall Collection | National Library of Australia". Nla.gov.au. Retrieved 15 January 2017.
- "Monash role for Divall". Theage.com.au. 24 March 2011. Retrieved 15 January 2017.
- "CD91241 LOHENGRIN Remedios, Bureau, Melbourne 1985". Operapassion.com. 12 June 2012. Retrieved 15 January 2017.
- "Buy classical CDs, opera CDs, & DVDs online". Presto Classical. Archived from the original on 16 January 2017. Retrieved 15 January 2017.
- "CD5954 Donizetti Maria Stuarda 1976 Melbourne". Operapassion.com. 24 July 1976. Retrieved 15 January 2017.
- "DVD: Handel: Alcina – Sutherland – Russell – Dixon – Campbell – Winslade – Bennett; Divall". Operapassion.com. 1987. Retrieved 15 January 2017.
- "It's an Honour – Honours – Search Australian Honours". Itsanhonour.gov.au. Retrieved 15 January 2017.