FitzGerald, the twelfth of thirteen children, was brought up in the country town of Kilmore, Victoria, and moved to the UK in 1991. She started writing while working as a criminal justice social worker, latterly with serious sex offenders in Glasgow's Barlinnie Prison.

FitzGerald began as a screenwriter, producing a series of educational children's dramas for BBC Scotland. She subsequently sold a number of screenplays, but none was ultimately produced and — frustrated by the film and television industry — she turned to novel-writing. She is a Bestseller in Holland and Germany.

Her first book, Dead Lovely, was completed in 2006. It was picked up by publishers Ambo/Anthos(Netherlands) and subsequently by Allen & Unwin (Australia/ New Zealand), Faber & Faber (UK), Calmann-Levy (France) and Piemme (Italy).

"The Devil's staircase" was published in 2009, Polygon.

Helen's third novel was "My Last Confession", 2009 Faber & Faber.

The fourth novel, "Bloody Women" also came out in 2009, Polygon.

Three books are currently due to be published;

"Amelia O'Donohue is SO not a virgin", a teen novel coming out November 2010 in America, Source Books.

"The Donor", Helens 5th adult novel due to come out in the UK Spring 2010, Faber & Faber.

"Hot Flush", for reluctant readers, due 2011, Barrington Stoke.

Some commentators noted that FitzGerald's first book, while generally described as a crime novel, did not follow the traditional rules of the genre. They argued that it belonged to a different, more psychologically complex tradition, characterised by the dark humour and flawed anti-heroines of writers such as Tama Janowitz and Fay Weldon. Novelist Mark Abernethy wrote of FitzGerald: "She has managed to do what Fay Weldon did in The Life and Loves of a She-Devil, which is to find the joke in what appals us Authorsites.co.uk : Dead Lovely."

Australian critic Sally Murphy described the novel as compelling but hard to classify, with "elements of chick-lit mixed with ghastly scenes of murder and retribution" Book Review: Dead Lovely, by Helen Fitzgerald, while Adelaide writer Cath Kenneally highlighted FitzGerald's technique of underpinning audacious and potentially shocking material - "working blue" - with "sociological acumen" The Adelaide Review : Archives.

On 31 March 2010 "The Devil's Staircase" was nominated for the 2010 Spinetingler Award in America, despite the book never being published there.