Mufaddal Saifuddin is the spiritual leader, the 53rd Da'i al-Mutlaq of one million Dawoodi Bohras, a subgroup of the Tayyibi, Mustaali, Ismaili Shia branch of Islam. He is the second son of the 52nd Da'i al-Mutlaq, Mohammed Burhanuddin, whom he succeeded in 2014. He is the Chancellor of Aligarh Muslim University and Jamia Miliya Islamia University situated in India. He has led a number of cultural, social, and economic initiatives. In Islamic Cairo, he rebuilt shrines of the Ahl al-Bayt and led the restoration of medieval Fatimid architecture, notably Al-Anwar Mosque, Al-Aqmar Mosque, Al-Juyushi Mosque, and Lulua Mosque. In Yemen, he has spearheaded several campaigns to improve socio-economic conditions of the inhabitants of the Haraaz region, introducing sustainable agricultural systems, improving local infrastructure and providing equal access to education for children.

The term Da'i al-Mutlaq literally meaning 'the absolute, or unrestricted, missionary', is the most senior spiritual rank and office in Tayyibi Isma'ilism. The Da'i al-Mutlaq has headed the Tayyibi community since the seclusion of the 21st Tayyibi Imam, at-Tayyib Abu'l-Qasim, traditionally placed in 528 AH/1134 AD.