Ali Ardashir Larijani (Persian: علی اردشیر لاریجانی; born 1958 in Najaf, Iraq) is an Iranian philosopher, politician and the chairman/speaker of the Iranian parliament. Larijani was the secretary of the Supreme National Security Council from August 15, 2005 to October 20, 2007, appointed to the position by President Mahmoud Ahmadinejad, replacing Hassan Rowhani. Acceptance of Larijani's resignation from the secretary position was announced on October 20, 2007 by Gholamhossein Elham, the Iranian government's spokesman, mentioning that his previous resignations were turned down by President Ahmadinejad.

Larijani is one of the two representatives of the Supreme Leader Ali Khamenei to the council, the other being Hassan Rowhani. In his post as secretary he effectively functioned as the top negotiator on issues of national security, including Iran's nuclear program.

Ali Larijani is a son of Ayatollah Hashem Amoli, a brother of Sadegh Larijani (President of the Judicature), Mohammad Javad Larijani, Bagher Larijani (chancellor of Tehran University of Medical Sciences), and Fazel Larijani (Iran's cultural attachée in Ottawa). He is also the son-in-law of Ayatollah Morteza Motahhari, having married his daughter Farideh, and also a cousin of Ahmad Tavakkoli (Larijani's and Tavakkoli's mothers are sisters).