Nicole, who won a Golden Globe for her role in Big Little Lies, is teaming up with the Australian author again, taking on both the lead role and producing responsibilities for the film adaption.
Set for a November release, Moriarty's latest book takes place at a remote health resort where several people are gathered to reboot their lives.
Frances Welty, who Kidman is set to play, is a former bestselling romance novelist attempting to mend a broken heart. But knowing Moriarty, our guess is there'll be more than meets the eye with this book.
On working with Nicole again, the best-selling author told The Hollywood Reporter, "I'm so very happy and thrilled to once again be working with Nicole, Per [Saari] and Bruna [Papandrea]."
"They are such talented, passionate people and I have no doubt that whatever they do with my Nine Perfect Strangers, it will be brilliant. I'm honoured by their faith in this book - even before I'd written 'the end' they believed in it, and I just feel very lucky to have had them come into my life," she continued.