Mohammad Hassan Mirza (; 20 November 1899 – 7 January 1943) was the last crown prince of the Qajar dynasty, who served as the Regent of Iran from 1924 till 1925, after his brother, Ahmad Shah Qajar, permanently departed from Iran in late 1923. In 1924, he successfully halted Reza Khan's attempt to declare Iran a republic, unifying a parliamentary alliance against the legislative votes required to change Iran's constitution from a monarchy to a republic. The following year, Reza Shah deposed the Qajar dynasty and installed himself as Shah of Iran in 1925, Mohammad Hassan and his family were sent into permanent exile to England.
In 1930, he declared himself the rightful heir to the crown as pretender to the throne. He died on 7 January 1943 in Maidenhead, England and was buried in Karbala, Iraq.
Tension with Ahmad Shah Qajar
thumb | 220x124px | right | Photograph of Mohammad Hassan Mirza, Ahmad Shah Qajar and Reza Khan Pahlavi
Even before the dethronement of his brother Ahmad Shah Qajar by Reza Shah, he was still an inconsequential figure in Iranian politics. This was not from a lack of trying however; in early March 1921, Mohammad Hassan Mirza approached the British legation with proposals to supplant his brother, the shah of Iran at the time. and that "he [Mohammad Hassan Mirza] is prepared to form new government as he considers the Shah useless...".
- Monaco: Grand Cross of the Order of Saint-Charles (14 January 1915)
Offspring
- Prince Soltan Hosein Mirza (25 August 1916, Tabriz-1986, Canada)
- Prince Soltan Hamid Mirza (23 April 1918, Tabriz-5 May 1988, London)
- Prince Rokn al-Din Mirza (1923, Tehran-1996, Canada)
- Princess Shmas Aghdas (1919, Tehran-1991, Paris)
- Princess Giti Afruz (1922, Tehran-2022, New York City)
Government positions held
- Governor-General of Azerbaijan (1918)