How does Iran choose its supreme leader, and who will be the next supreme leader?

Khamenei’s death in a joint US-Israeli airstrike has forced Iran’s leadership into an urgent process to select a new supreme leader.

Under Iran’s constitution, the supreme leader is appointed by the Council of Experts, an 88-member body of clerics elected by the people every eight years. Candidates for Congress are first vetted by the Guardian Council, which strictly controls who can run.

When a vacancy occurs in a position, a parliament is convened to deliberate and select a successor. Decisions require a simple majority vote.

In the interim, an interim three-member Leadership Council will assume the duties of the Supreme Leader until a successor is formally appointed.

On Sunday, local media reported that the temporary council is made up of President Massoud Pezeshkian, Attorney General Gholam-Hossein Mohseni-Ejei, and the head of the Guardian Council, Mullah Alireza Alafi.

Although the council’s powers are strictly transitional, the Assembly of Experts retains the sole constitutional authority to select Iran’s next supreme leader.

On Polymarket, traders are pegging Mohseni Ejei as a close favorite with around 18%. Other front-runners include Arafif and Iranian cleric Hassan Khomeini.

The results for ‘deprecation of positions’ remain close, suggesting that while the market remains tilted toward individual replacements, there is meaningful speculation about possible structural changes to the positions themselves.

The main candidates are:

Mohseni-Ejei has been Iran’s chief judge since July 2021, overseeing the country’s judiciary and overseeing legal policy across the Islamic Republic.

Previously, he served as Attorney General from 2009 to 2014, as First Deputy Director and Spokesperson of the Department of Justice from 2014 to 2021, and before that served in national security roles including Minister of Information from 2005 to 2009.

He is also a longtime member of the Council of Expedient Discrimination, an important advisory body to Iran’s leadership, and his career has spanned senior positions in both the judiciary and security services.

The Council on Foreign Relations said Khomeini is the grandson of Islamic Republic founder Ayatollah Ruhollah Khomeini and could theoretically serve as a bridge between the revolutionary regime and reform-minded voters.

The CFR suggested that elevating someone like him could help maintain the Islamic Republic’s core structures, reduce Iran’s international isolation, and address popular grievances at home.

Mr. Alafi is a senior Iranian cleric and an influential figure within the Islamic Republic’s religious and political hierarchy. He has risen through the ranks of the clergy through a series of important appointments, including chairman of the Iranian Seminary, leader of Qom’s Friday prayers, and member of both the Guardian Council and the Council of Experts, which are constitutionally tasked with selecting the supreme leader.

Mr. Alafi’s role in shaping theological education and vetting political candidates made him a central figure in Iran’s clerical power structure.

Under Article 111 of Iran’s constitution, upon the death or incapacity of the Supreme Leader, an interim leadership council is to be established immediately to exercise his powers until a successor is elected.

The constitution does not set a strict deadline for the Assembly of Experts to appoint a new leader, but it does state that Parliament must act “within the shortest possible time.”

But analysts warned that a formal succession process could involve intense elite negotiations and widespread geopolitical uncertainty.

Emeritus Professor Amin Saikal from the University of Western Australia said while Mr Mohseni-Ejei may appear to be the frontrunner, the panel could choose another member or someone from outside the panel.

“There’s going to be a huge horse trade,” he told CNBC, adding, “There could be a compromise with whoever comes along.”

He added that a hard-line successor would likely continue Khamenei’s confrontational stance and security-first policies, while a more moderate figure might seek limited reforms aimed at easing domestic regulations and improving external relations to ease sanctions pressure.

Separately, Michael McFaul, a former U.S. ambassador to Russia and a professor at Stanford University, noted that historically air operations have rarely led to regime change, and questioned how the current U.S. strikes, which target military assets rather than domestic repressive measures, could lead to the broader regime change that Washington has signaled.