The Topkapı or Seraglio Octateuch (Topkapi Graecus 8) is a 12th-century Byzantine illuminated manuscript of the Octateuch. It is named after its location in the library of the Topkapı Palace in Istanbul, the former residence ("seraglio") of the Ottoman sultans. It was sponsored by the Byzantine prince Isaac Komnenos, and remained unfinished due to the latter's death.