Ghazi Amir Amanullah Khan (June 1, 1892 - April 25, 1960) was the ruler of Afghanistan from 1919 to 1929. He led Afghanistan to independence from Britain, and his rule was marked by dramatic political and social change.

Amanullah Khan was the son of the Amir Habibullah Khan. When Habibullah was assassinated on February 20, 1919, Amanullah was already the governor of Kabul and was in control of the army and the treasury. He quickly seized power, imprisoned any relatives with competing claims to the Amirship, and gained the allegiance of most of the tribal leaders.

Russia had recently undergone its Communist revolution, leading to strained relations between the country and Britain. Amanullah Khan recognized the opportunity to use the situation to gain Afghani independence. He led a surprise attack against the British on May 3, 1919, beginning the third Anglo-Afghan war. After initial successes, the war quickly became a stalemate as Britain was still dealing with the costs of World War I. An armistice was reached in 1921, and Afghanistan became an independent nation.

Amanullah enjoyed quite a bit of early popularity within Afghanistan and he used his influence to modernize the country. Emulating Reza Shah of Iran, Amanullah created new cosmopolitan schools for both boys and girls in the region and overturned centuries-old traditions such a strict dress codes for women. He created a new capital city and increased trade with Europe and Asia. He also advanced a modernist constitution that incorporated equal rights and individual freedoms. Unfortunately, this rapid modernization created a backlash, just as it had for Reza Shah in Iran, and a reactionary uprising known as the Khost rebellion was surpressed in 1924.

At the time, Afghanistan's foreign policy was primarily concerned with the rivalry between the Soviet Union and Britain. Each attempted to gain the favor of Afghanistan and foil attempts by the other power to gain influence in the region. This effect was inconsistent, but generally favorable for Afghanistan; Amanullah was even able to establish a limited air force consisting of donated Soviet planes.

After Amanullah travelled to Europe in late 1927, opposition to his rule increased. An uprising in Jalalabad culminated in a march to the capital, and much of the army deserted rather than resist. In early 1929, Amanullah abdicated and was exiled. He settled in Europe, where he lived until his death. Very few of his many reforms were continued once he was no longer in power.