McMullen has a degree in physics and history from Melbourne University (1974), a postgraduate degree in library and information science, and a PhD in Medieval Literature. He was a professional musician in the 1970s, concentrating on singing and guitar playing.

His first novel was originally published in Australia as two separate books, Voices In The Light (1994) and Mirrorsun Rising (1995). They were rewritten and combined for a publication in the US as Souls In The Great Machine (1999), which, in turn, became the first volume of the Greatwinter trilogy, a unique mix of the generally anti-genres Steampunk and Cyberpunk.

Novels

Greatwinter

• Souls in the Great Machine (1999, a rewritten version of Voices in the Light and Mirrorsun Rising)
• The Miocene Arrow (2000)
• Eyes of the Calculor (2001)

The Moonworlds Saga

• Voyage of the Shadowmoon (2002)
• Glass Dragons (2004)
• Voidfarer (2006)
• The Time Engine (2008)

Other novels

• Voices in the Light (1994)
• Mirrorsun Rising (1995)
• The Centurion's Empire (1998)
• The Ancient Hero (2004, part of the Quentaris Chronicles)
• Before the Storm (2007)

Collections

• Call to the Edge (1992)
• Walking To The Moon (2007)

Non-fiction

• The MUP Encyclopaedia of Australian Science Fiction & Fantasy (1998, assistant editor with Paul Collins)
• A History of Australian Science Fiction (1999 with Russell Blackford and Van Ikin)

Short fiction

• "At the Focus" (1986 with Paul Collins) in Eidolon Spring 1990 (ed. Jeremy G. Byrne)
• "The Deciad" (1986) in Call to the Edge
• "The Colors of the Masters" (1988) in The Magazine of Fantasy & Science Fiction March 1988 (ed. Edward L. Ferman)
• "While the Gate Is Open" (1990) in The Magazine of Fantasy & Science Fiction February 1990 (ed. Edward L. Ferman)
• "Alone in His Chariot" (1991) in Eidolon Summer 1991 (ed. Jeremy G. Byrne)
• "The Dominant Style" (1991) in Aurealis #4 (ed. Stephen Higgins, Dirk Strasser)
• "The Eyes of the Green Lancer" (1992) in Call to the Edge
• "Destroyer of Illusions" (1992) in Call to the Edge
• "The Porphyric Plague" (1992) in Intimate Armageddons (ed. Bill Congreve)
• "Pax Romana" (1992) in Call to the Edge
• "The Devils of Langenhagen" (1992) in Call to the Edge
• "An Empty Wheelhouse" (1992) in Analog Science Fiction and Fact January 1992 (ed. Stanley Schmidt)
• "Souls in the Great Machine" (1992) in Universe 2 (ed. Karen Haber, Robert Silverberg)
• "The Glasken Chronicles" (1992) in Eidolon Autumn 1992 (ed. Jeremy G. Byrne)
• "Pacing the Nightmare" (1992) in Interzone May 1992 (ed. David Pringle, Lee Montgomerie)
• "A Greater Vision" (1992) in Analog Science Fiction and Fact October 1992 (ed. Stanley Schmidt)
• "The Way to Greece" (1993) in Eidolon Winter 1993 (ed. Jeremy G. Byrne, Jonathan Strahan)
• "Charon's Anchor" (1993) in Aurealis #12 (ed. Stephen Higgins, Dirk Strasser)
• "The Miocene Arrow" (1994) in Alien Shores: An Anthology of Australian Science Fiction (ed. Peter McNamara, Margaret Winch)
• "The Blondefire Genome" (1994) in The Lottery: Nine Science Fiction Stories (ed. Lucy Sussex)
• "A Ring of Green Fire" (1994) in Interzone November 1994 (ed. David Pringle, Lee Montgomerie)
• "Lucky Jonglar" (1996) in Dream Weavers (ed. Paul Collins)
• "The Weakest Link" (1996, written as Roger Wilcox) in Dream Weavers (ed. Paul Collins)
• "Slow Famine" (1996) in Interzone May 1996 (ed. David Pringle)
• "Queen of Soulmates" (1998) in Dreaming Down-Under (ed. Jack Dann, Janeen Webb)
• "Chronicler" (1998) in Fantastic Worlds (ed. Paul Collins)
• "Rule of the People" (1998) in Aurealis #20/21, (ed. Stephen Higgins, Dirk Strasser)
• "Souls in the Great machine" (1999) an excerpt in The Centurion's Empire
• "New Words of Power" (1999) in Interzone August 1999 (ed. David Pringle)
• "Colours of the Soul" (2000) in Interzone February 2000 (ed. David Pringle)
• "Unthinkable" (2000) in Analog Science Fiction and Fact June 2000 (ed. Stanley Schmidt)
• "Mask of Terminus" (2000) in Analog Science Fiction and Fact October 2000 (ed. Stanley Schmidt)
• "Voice of Steel" (2001)
• "Tower of Wings" (2001) in Analog Science Fiction and Fact December 2001 (ed. Stanley Schmidt)
• "SVYAGATOR" (2002) in Andromeda Spaceways Inflight Magazine #3 (ed. Ian Nichols)
• "Walk to the Full Moon" (2002) in The Magazine of Fantasy & Science Fiction December 2002 (ed. Gordon Van Gelder)
• "The Cascade" (2004) in Agog! Smashing Stories (ed. Cat Sparks)
• "The Empire of the Willing" (2005) in Future Washington (ed. Ernest Lilley)
• "The Engines of Arcadia" (2006) in Futureshocks (ed. Lou Anders)
• "The Twilight Year" (2008) in The Magazine of Fantasy & Science Fiction January 2008 (ed. Gordon Van Gelder)
• "The Constant Past" (2008) in Dreaming Again (ed. Jack Dann)
• "The Spiral Briar" (2009) in The Magazine of Fantasy & Science Fiction April-May 2009 (ed. Gordon Van Gelder)
• "The Art of the Dragon" (2009) in The Magazine of Fantasy & Science Fiction August-September 2009 (ed. Gordon Van Gelder)

Essays

• Beyond Our Shores (1990) in Eidolon Winter 1990
• The High Brick Wall (1990) in Eidolon Spring 1990 (ed. Jeremy G. Byrne)
• Not In Print but Worth Millions (1991) in Eidolon Winter 1991 (ed. Jeremy G. Byrne)
• Book Review (1991) in Aurealis #5 (ed. Stephen Higgins, Dirk Strasser)
• Going Commercial and Becoming Professional (1991) in Eidolon Spring 1991 (ed. Jeremy G. Byrne)
• Australian SF Art Turns 50 (1992) in Eidolon Summer 1992 (ed. Jonathan Strahan, Jeremy G. Byrne)
• Far from Void: The History of Australian SF Magazines (1992) in Aurealis #7 (ed. Stephen Higgins, Dirk Strasser)
• Skirting the Frontier (1992) in Eidolon Autumn 1992 (ed. Jeremy G. Byrne)
• Showcase or Leading Edge: Australian SF Anthologies 1968-1990 (1992) in Aurealis #9, (ed. Stephen Higgins, Dirk Strasser)
• From Science Fantasy to Galileo (1992) in Eidolon Spring 1992 (ed. Jeremy G. Byrne, Jonathan Strahan)
• Australian Content: The State of Quarantine (1993) in Eidolon Summer 1993 (ed. Jeremy G. Byrne, Jonathan Strahan)
• Australian Content: Suffering for Someone Else's Art (1993) in Eidolon Autumn 1993 (ed. Jonathan Strahan, Jeremy G. Byrne)
• Protection, Liberation and the Cold, Dangerous Universe: The Great Australian SF Renaissance (1993) in Aurealis #11, (ed. Stephen Higgins, Dirk Strasser)
• No Science Fiction Please, We're Australian (1993) in Eidolon Winter 1993 (ed. Jeremy G. Byrne, Jonathan Strahan)
• The Quest for Australian Fantasy (1994, with Steven Paulsen) in Aurealis #13, (ed. Stephen Higgins, Dirk Strasser)
• Australian Content: The Great Transition (1994) in Eidolon Winter 1994 (ed. Jonathan Strahan, Jeremy G. Byrne)
• The Hunt for Australian Horror Fiction (1994, with Steven Paulsen) in Aurealis #14 (ed. Stephen Higgins, Dirk Strasser)
• A History of Australian Horror (1995, with Bill Congreve and Steve Paulsen) in Bonescribes: Year's Best Australian Horror: 1995 (ed. Bill Congreve, Robert Hood)
• SF in Australia (1995, with Terry Dowling) in Locus January 1995 (ed. Charles N. Brown)
• Australian Content: Recognition Australian Style (1995) in Eidolon Summer 1995 (ed. Jeremy G. Byrne)
• Australian Contemporary Fantasy (1997, with Steven Paulsen)
• George Turner and the Nova Mob (1997) in Eidolon, Issue 25/26 Spring 1997 (ed. Jonathan Strahan, Jeremy G. Byrne, Richard Scriven)
• The Road to 1996 (1998, with Terry Dowling) in Nebula Awards 32 (ed. Jack Dann)
• The British Benchmark (1999) in Interzone August 1999 (ed. David Pringle)
• Time Travel, Times Scapes, and Timescape (2000, with Russell Blackford, Alison Goodman, Damien Broderick, Aubrey Townsend, Gregory Benford) in The New York Review of Science Fiction August 2000, (ed. Kathryn Cramer, David G. Hartwell, Kevin J. Maroney)
• 25 (Celebrating 25 Years of Interzone) (2007) in Interzone September-October 2007 (ed. Andrew Hedgecock, Jetse de Vries, Andy Cox)

Ditmar Awards

1991 Best Australian Short Fiction - While the Gate is Open

1992 Best Short Fiction - Alone in His Chariot; William Atheling Jr. Award for Criticism - Going Commercial

1993 William Atheling Jr. Award for Criticism - Australian SF Art Turns 50

1996 Best Australian Long Fiction - Mirrorsun Rising; William Atheling Jr Award for Criticism - The Hunt for Australian Horror Fiction (together with Steven Paulsen and Bill Congreve)

1998 William Atheling Jr Award for Criticism - Fantasy in Australia (together with Steven Paulsen)

2000 William Atheling Jr Award for Criticism - Strange Constellations (together with Van Ikin and Russell Blackford)

Aurealis Awards

1998 Best Novel - The Centurion's Empire

2001 Best Novel - The Miocene Arrow

2003 Best Short Story -Walk to the Moon

Analog Reader's Award

2002 Best Novellette - Tower of Wings

Nova Fantastyka Reader's Award

2003 Best Foreign Story - Voice of Steel

Festivale Online Magazine, Summer 2008-09, ISSN 1328-8008