You Only Live Twice is the eleventh novel in Ian Fleming's James Bond series of stories. It was first published in 1964. It was the last Fleming novel published in his lifetime. It is the concluding chapter in what is known as the "Blofeld Trilogy," following after Thunderball and On Her Majesty's Secret Service.

The story starts eight months after the murder of Tracy Bond, which occurred at the end of On Her Majesty's Secret Service. James Bond is drinking and gambling heavily and making mistakes on his assignments when, as a last resort, he is sent to Japan on a semi-diplomatic mission. Whilst there he is challenged by the head of the Japanese Secret Service to kill Dr. Guntram Shatterhand.