マルコによる福音書
The Secret Gospel of Mark or the Mystic Gospel of Mark (), also the Longer Gospel of Mark, is a putative longer and secret or mystic version of the Gospel of Mark. The gospel is mentioned exclusively in the Mar Saba letter, a document of disputed authenticity, which is said to be written by Clement of Alexandria (c. AD 150–215). This letter, in turn, is preserved only in photographs of a Greek handwritten copy seemingly transcribed in the eighteenth century into the endpapers of a seventeenth-century printed edition of the works of Ignatius of Antioch.