Mark Shirrefs and long-time collaborator John Thomson met while undergraduates at the Victorian College of the Arts Drama School in 1976. They worked separately in the performing arts for some years, specialising as comedy directors and writers. Shirrefs co-founded the Flying Fruit Fly Circus and directed plays for the Murray River Performing Group and Theatreworks. Shirrefs and Thomson completed the Swinburne Institute of Technology postgraduate film course in 1982 and 1986 respectively.

Their first collaboration was 1990's Let The Blood Run Free, a satire of day-time hospital soap operas, which had begun life as an improvished stage show in Melbourne but was brought to television after the intervention of Ian McFadyen. Shirrefs and Thomson are, however, best known for their extensive body of work in children's science-fiction and fantasy television, which began in 1989 with The Girl from Tomorrow for Channel 9. It won an AWGIE Award for best original children's script and sold in over sixty countries. The 1991 sequel series, Tomorrow's End, won an ATOM Award and had similar commercial success. Both series were novelised and published by Hodder and Stoughton.

In 1995, Shirrefs and Thomson developed Spellbinder, another children's science-fiction/fantasy series, for Channel 9. A co-production between Film Australia and Polish Television, it won two ATOM awards, an AWGIE award, and an AFI award. Two Spellbinder novels were published in 1995. Spellbinder was followed by a sequel, Spellbinder II: Land of the Dragon Lord.

Their subsequent collaborations include scripts for Mission: Top Secret, Pig's Breakfast, and Scooter: Secret Agent.

Shirrefs has also written scripts independent of his long-time collaboration with Thomson, including for Snake Tales, Mal.com, and Conspiracy 365.

In 2005, Shirrefs penned the short, animated steam-punk film The Mysterious Geographic Explorations of Jasper Morello with Anthony Lucas. The film was nominated for an Oscar, a BAFTA, and an AFI Award, and won numerous other awards.

Shirrefs also lectured in creative writing at the RMIT University.

Sources:

Paul Davies, 'Writing Kids' TV Talking to Mark Shirrefs', Metro Magazine 133 (2002): pp.134-139.

'Shirrefs, Mark (1952-)' in The MUP Encyclopaedia of Australian Science Fiction & Fantasy. Ed. Paul Collins. Melbourne: Melbourne UP, 1998, pp.159-160.