Soltan Mohammad Mirza (Persian: سلطان محمد میرزا; 7 June 1812 – 1899) better known by his honorific title Sayf ol-Dowleh (Persian: سیف الدوله) was an Iranian prince of the Qajar dynasty and thirty-ninth son of Fath-Ali Shah, king of Qajar Iran. He was the governor of Isfahan between 1820 to 1835 and contributed to its restoration after the damage it suffered in the civil war between Zand sovereigns and Agha Mohammad Khan, rebuilding several of the Safavid pavilions and designing his own palace.