Sleeping with the Enemy: Coco Chanel's Secret War

Sleeping with the Enemy: Coco Chanel's Secret War is a 2011 book by journalist Hal Vaughan, it was published by Knopf Doubleday Publishing Group, now part of Penguin Random House. The book is a biography of French fashion designer Coco Chanel, detailing her life from humble beginnings growing up in relative poverty, to her meteoric rise in French and British society and emergence as a fashion icon.

The book also details her active collaboration with the Nazi intelligence service, the Sicherheitsdienst, during the second World War. Although it had been known that Chanel was a mistress of a Nazi officer, the extent of her Nazi collaboration during the war had previously been unknown prior to the publication of the book.