Ali Hosseini Khamenei, commonly known as Ayatollah Ali Khamenei, was born on April 19, 1939, in Mashhad, Iran, into a modest clerical family; his father, Seyyed Javad Khamenei, was a mujtahid. He began his education in Islamic studies early, learning to read the Quran in childhood and attending a theological seminary in Mashhad. At 18, he traveled to Najaf, Iraq, to study Shia jurisprudence but returned at his father's request. He later moved to Qom in the late 1950s to study under prominent scholars, including Ayatollah Ruhollah Khomeini. During the 1960s and 1970s, Khamenei became actively involved in opposition to the Pahlavi monarchy, aligning with Khomeini against the White Revolution in 1962, leading to multiple arrests and exiles by the Shah's regime. His early career included teaching at seminaries, writing Islamic works, and translating books, establishing him as an Islamic jurist, poet, and translator.

Following the 1979 Islamic Revolution, Khamenei held key positions such as deputy defense minister and overseer of the Islamic Revolutionary Guard Corps (IRGC). From October 1981 to August 1989, he served as the third President of Iran, guiding the country through the Iran-Iraq War, consolidating revolutionary gains, and surviving a 1981 assassination attempt that partially paralyzed his right arm; he was re-elected president twice. Upon Khomeini's death in 1989, the Assembly of Experts appointed Khamenei as the second Supreme Leader of the Islamic Republic of Iran, the highest political and religious authority, a position he has held for over three decades, making him the longest-serving head of state in the Middle East.

As Supreme Leader, promoted to the rank of Ayatollah in 2015, Khamenei wields ultimate authority over Iran's political, military, religious, and judicial affairs, serving as the final decision-maker on state matters. He issues fatwas, guides the nation’s ideological direction, and oversees vast influence networks through bonyads (foundations) and the IRGC. His ultimate authority extends to Iran's nuclear program and its strategy toward Israel. Under his leadership, Iran has pursued policies emphasizing Islamic governance, resistance to Western influence, and support for regional proxies such as Hezbollah and the Houthis, while maintaining a hardline stance on Israel and the West. His tenure has been marked by controversies including suppression of domestic dissent, notably during the 2009 Green Movement protests, and advancing Iran's nuclear program amid international sanctions and tensions with Western powers, including adversarial relations with figures like former U.S. Secretary of State Mike Pompeo.

Personally reclusive, Khamenei has been married to Khojaste Bagherzadeh since 1964, with six children. He has interests in poetry and literature, organizing poetry sessions and mentoring younger poets. He lives in Tehran, though details of his personal wealth remain opaque.