Heather O'Neill was born in Montreal and attended McGill University.
She published her debut novel, Lullabies for Little Criminals, in 2006. The novel won the Canada Reads competition (2007) and was awarded the Hugh Maclennan Award (2007). It was nominated for eight other awards included the Orange Prize, the Governor General's Award and the IMPAC Dublin Literary Prize. It was an international bestseller.
Her books The Girl Who Was Saturday Night (2014) and Daydreams of Angels (2015) were both shortlisted for the Giller Prize.
Her third novel The Lonely Hearts Hotel will be published in February 2017.
Her credits also include a screenplay, a book of poetry, and contributions to The New York Times Magazine, This American Life, The Globe and Mail, Elle Magazine, The Walrus and Rookie Magazine.