| Sayf ol-Dowleh | |
|---|---|
 Portrait of Sayf ol-Dowleh, signed by Seyyed Mirza, c. 1830-1835 | |
| Born | Soltan Mohammad Mirza 7 June 1812 Tehran |
| Died | 1899 (aged 86–87) Malayer |
| Burial | Malayer |
| House | Qajar dynasty |
| Father | Fath-Ali Shah |
| Mother | Taj ol-Dowleh |
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 and 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.
The later period of his governorship in Isfahan was marred by riots, banditry along the roads and his rivalry with Mohammad Bagher Shafti, a major Shi'ia clergy figure, which resulted in a Jihad being invoked against Sayf ol-Dowleh. He suppressed the Jihad, but Isfahan was damaged again and a famine followed. Mohammad Shah ousted him and appointed Khosrow Khan Gorji in his stead. Sayf ol-Dowleh spent his days traveling and died in 1899 in Malayer. Unusually for his time, Sayf ol-Dowleh only married once, and later divorced his wife, Bahar Khanum. He had no children. Like many of his siblings, he loved poetry and writing, and was the author of several travelogues and a divan.