Sayyid Abd ar-Rahman al-Haydari al-Kaylani (1841-1927) was the first prime minister of modern Iraq. Born to a prominent Baghdad family that had founded the Sufi mystical order of Islam, al-Kaylani was chosen in 1920 to head the Iraqi Council of Ministers following the disolution of the Ottoman Empire. He used his influence to oppose the appointment of Faisal of Syria as king of Iraq and resigned his post when his efforts were defeated. Nevertheless, Faisal reappointed him as prime minister in order to curb opposition.

In 1922 Kaylani negotiated the first Anglo-Iraqi Treaty, which ensured nominal independence for the country, though Britain maintained control of the military and foreign affairs, essentially establishing a Mandate in the country. Opposed to these results, Kaylani resigned shortly after. He died in 1927.