Her gritty take on Irish life continues its winning streak, this time in book form.
Her debut novel The Glorious Heresies, which traces the aftermath of an accidental murder in downtown Cork, won the £30,000 (S$53,000) Baileys Women's Prize For Fiction in June, beating Man Booker winner Anne Enright and finalist Hanya Yanagihara.
Two weeks later, it bagged the £10,000 Desmond Elliott Prize, set up in the name of the late publisher and literary agent and given to the year's best debut novel.
Novelist Iain Pears, who chaired the judging panel for the prize, called McInerney "a major literary figure of the next generation".
McInerney says: "It's so important for emerging writers to feel that sense of support from more established voices. Certainly, I've benefited from it.
"Ireland, in particular, has a great sense of community around literature, which I think makes publishing seem more accessible to new writers. I'd like to be able to contribute to that."
In her novel, the mother of Cork's most feared gangster accidentally kills an intruder in her home, setting off a wave of consequences for a ragtag cast of characters who exist on the fringe of society, among them a teenage drug dealer and his alcoholic father, and a prostitute.
But while The Glorious Heresies is laden with dark ingredients - murder, prostitution, arson - it is far from a bleak read. McInerney manages to weave a tale that is both tender and lively, by turns poetic and side-splittingly funny.
Hiberno-English, the set of English dialects written and spoken in Ireland, lends itself easily to humour, she explains.
"It's animated, with great turns of phrase," she says. "It's more unusual for an Irish writer not to be funny, especially those of us who work with vernacular... and the Irish have a great appreciation for dark humour."
But she was surprised to find some people telling her how "male" they found the book.
"It's so strange. There's great diversity in women writers' voices, so it's confusing when someone feels the need to 'gender' a novel or a piece of writing," she says.
"Is it because the book is violent? Is it because it's profane? Is it because it's action-heavy? None of these styles or themes is particular to male writers, of course, but some readers still find it notable when a woman writes something dark or transgressive."
She took just four months in the summer of 2013 to write the first draft. She has already charged on to her next book, which is slated for publication next year and will also tackle tough issues in working-class Cork.
It is an exciting time for Irish literature, she says, with a new wave of work coming from writers such as Kevin Barry and Belinda McKeon.
"One contributory factor was the shift in our social landscape after the economic crash. Many writers might feel compelled to try to make sense of this 'new' Ireland," she says.
"Another factor is that, in Ireland, we have exciting literary magazines, journals and independent publishers, so new writers have a lot of potential outlets for their work and might feel reasonably confident that they will find readers if they're willing to try."
• The Glorious Heresies (2015, John Murray, $19.94) is available at Books Kinokuniya.
Recent works by Irish writers
Irish fiction has been flourishing in recent years, with strong new voices making themselves known. Check out these recent works.
YOUNG SKINS (2013) By Colin Barrett
US$11.29 (S$15.30)/ Amazon.com
The Celtic Tiger is dead and it has left the fictional Irish town of Glanbeigh mauled. Barrett's debut short-story collection traces a staggering range of trials and tribulations in a rundown town hit hard by the tanking of the Irish economy. Its denizens lead small-town lives dogged by trouble and struggling with vice and the lack of money and opportunities.
The book has won a string of honours, including the Frank O'Connor International Short Story Award and the Guardian First Book Award.
BEATLEBONE (2015) By Kevin Barry
$19.94/Books Kinokuniya
It is 1978. John Lennon, soon entering his 40s and well past his Beatles days, has left New York City on a quest to find an island off the west coast of Ireland that he purchased on impulse 11 years ago.
All he wants is to spend a few days on the island to find inner peace. But misadventures await him and his shape-shifting Irish driver and fixer Cornelius.
Odd and exciting, this wildly imaginative book won the Goldsmiths Prize last year.
MULTITUDES (2016) By Lucy Caldwell
$27.97/Books Kinokuniya
In her first short-story collection, Caldwell shows what it means to grow up, through the eyes of a diverse series of young female protagonists.
She plumbs that experience for heartache and joy, writing with stunning colour about the rush of power the characters feel as they come into themselves, as well as how they face the sober realities of the adult world from the challenges of navigating sexuality to dealing with the sectarian divide in Ireland.
