Arthur Jermy Mounteney Jephson (1859–1908) was an English merchant seaman and army officer. He became an adventurer and African explorer, who accompanied H. M. Stanley on the Emin Pasha Relief Expedition, 1887–1889.
Jephson's diary from the expedition was published half a century after his death, and provides a record of the late Victorian African expeditions, of which this expedition was to be the last.
Note: The name is also spelled "Mountenay"