James Thomas Ley was born in South Australia, and grew up in the northern New South Wales town of Armidale. He studied literature at the University of New England and politics at the University of Melbourne and holds a PhD in English literature from the University of Western Sydney.
Ley has worked as a freelance critic since 1997. His writing has appeared in numerous publications, including The Age, The Australian, The Sydney Morning Herald, Australian Book Review, Australian Literary Review, Meanjin, Overland, Australian Literary Studies and the Times Literary Supplement. In January 2013, he became the founding editor of the Sydney Review of Books; in 2018, he remains contributing editor with the periodical.
He has twice acted as a judge in the fiction category for The Age Book of the Year competition.