Liane Moriarty (born November 1966) is an Australian author and the author of Big Little Lies.

After leaving school, Moriarty worked in advertising and marketing at a legal publishing company. She then ran her own company for a while before taking work as a freelance advertising copywriter. In 2004, after obtaining a masters degree at Macquarie University in Sydney her first novel Three Wishes, written as part of the degree, was published. Five further novels have been published.

Moriarty lives in Sydney with her husband and two children.