Prince Iraj Mirza (Persian: ایرج میرزا, literally Prince Iraj; October 1874 – 14 March 1926), titled Jalāl-ol-Mamālek (Persian: جلال‌الممالک), was a prominent Iranian poet. He was the son of Prince Gholam-Hossein Mirza. Iraj Mirza was known for his modern poetry, which often critiqued traditional customs. In addition to his original works, he translated literary pieces from French into Persian.

Iraj Mirza was born in October 1874 in Tabriz, northwestern Iran. He was a great-grandson of Fath Ali Shah Qajar, the second shah of the Qajar dynasty (r. 1797–1834). His father, Prince Gholam-Hossein Mirza, was the son of Prince Malek Iraj Mirza, who was himself a son of Fath Ali Shah.

Gholam-Hossein Mirza served as the poet laureate, or official court poet, for Mozaffar al-Din Mirza in Tabriz, since traditionally, all Crown Princes during the Qajar era resided in Tabriz. Mozaffar al-Din Mirza, later known as Mozaffar al-Din Shah, the Crown Prince of Iran at the time, was the son of Naser al-Din Shah Qajar, the fourth shah of the Qajar dynasty (r. 1848–1896).

Although some sources suggest that Iraj was privately educated, reliable evidence indicates that he attended a branch of the Dār ol-fonoon (House of Sciences and Techniques) in Tabriz. By the age of 15, Iraj was fluent in Persian, French, Arabic, and Azerbaijani. He was also skilled in the art of calligraphy, with his handwriting being regarded as highly artistic. Iraj Mirza remains recognized as one of Iran's renowned calligraphers.

In 1890, at the age of 16, Iraj Mirza married. By the age of 19, both his father and wife had died. Following his father's death, Iraj assumed the position of court poet for Mozaffar al-Din Mirza. In 1896, Mozaffar al-Din Mirza ascended to the throne as Mozaffar al-Din Shah and the 22 year old Iraj was given the title Head of Poets (Sadr o-Shoʻarā) (Persian: سردار الشعراء) and later received the title Jalāl ol-Mamālek.

A few years later, Iraj left the royal court and joined the Tabriz office of Ali Khan Amin al-Dowleh, the governor of Iranian Azarbaijan. During this period, he learned French and became familiar with Russian. In 1905, when Amin al-Dowleh was sent to Tehran, Iraj accompanied him and became involved in the Persian Constitutional Revolution. In 1907, Ahmad Ghavam (Qavam os-Saltaneh), a governmental authority, was assigned to Europe, and Iraj joined him. Two years later, Iraj returned to Tehran and began working as a staff member in the Office of Official Compositions (Dār ol-ʻenshā, Persian: دار الانشاء).

In 1915, Iraj's first son, Ja'afar Gholi Mirza, committed suicide due to psychological problems. In 1917, Iraj joined the newly established Ministry of Culture, and three years later, he transferred to the Ministry of Finance and Revenue. From 1920 to 1925, he served as a Revenue Officer in Mashhad, the capital city of Khorasan Province (now Razavi Khorasan), in northeastern Iran.

At the age of 51, Iraj returned to Tehran, where he died of a heart attack on March 14, 1926.