Mass'oud Mirza Zell-e Soltan ("Mass'oud Mirza the Sultan's Shadow (5 January 1850 in Tabriz – 2 July 1918 in Isfahan) or Massud Mirza was a Persian prince of the Qajar Dynasty; he was known as the "Yamin-al-Dowleh" ("Right Hand of the Government").
He was posted as the governor of Isfahan for over 35 years, and the governor of the Mazandaran, Fars, and Isfahan for a total of 40 years.