Muslims do not have one leader, like a pope. There are many many scholars who are well-respected by most Muslims, though.
Allah is the spiritual leader of muslims.
A kafir can not lead Muslims. Only a Muslim can lead Muslims.
Saladin led the Muslims in some of the Crusades.
I'm not Muslim but I think their leader is Mohammed.
Agakhan is leader of Ismaili muslims.
Jesus
Ali
saladin
Iman is not a religios leader. Iman is what Muslims call their faith.
An Imam
Imam, sheikh, Ayatuallah, ....
generally prophet Muhammad PBUH currently Imam Mahdi SA and Imam Khamenei ANSWER II Question is not clear ! A leader may be for a nation , for a party or for a team and not for a religion , as Islam is a religion , it can,t have a leader but Muslims can have a leader , at present there is no out standing leader of Muslims .