Abu Bakar Bashir (also Abubakar Ba'asyir, Abdus Somad, and Ustad Abu ("Teacher Abu"), born August 17, 1938, is an Indonesian Muslim cleric and leader of the Indonesian Mujahedeen Council (MMI).

He runs the Al-Mukmin boarding school in Ngruki, Central Java which he co-founded with Abdullah Sungkar in 1972. He was in exile in Malaysia for 17 years during the secular New Order administration of the President of Indonesia Suharto resulting from various activities, including urging the implementation of Sharia law.

Intelligence agencies claim he is the spiritual head of Jemaah Islamiyah (also known as JI) and has links with Al-Qaeda. Bashir, however, denies connections with Jemaah Islamiyah or terrorism stating he does not believe Jemaah Islamiyah exists.