Sultan Muhammadu Sa'ad Abubakar (born August 24, 1956 in Sokoto) is the 20th Sultan of Sokoto, the titular ruler of Sokoto in northern Nigeria, head of Jama'atu Nasril Islam (Society for the Support of Islam – JNI), and president-general of the Nigeria Supreme Council for Islamic Affairs (NSCIA).
As Sultan of Sokoto, he is considered the spiritual leader of Nigeria's fifty-nine million Muslims, roughly twenty-seven percent of the nation's population.
Sa'adu Abubakar succeeded his brother, Muhammadu Maccido, who died on ADC Airlines Flight 53, the flight crashed shortly after takeoff from Nnamdi Azikiwe International Airport and had been destined for Sokoto.