|Death:||17 July 2018|
Muhammad Ould Fahfu al-Massumi also known as al-Murabit al-Hajj or al-Hajj Ould Fahfu (1913 – 17 July 2018) was a Mauritanian centenarian and Islamic scholar.
Murabit al-Hajj was born in Mauritania in 1913. He devoted his life to worship, learning and teaching Islamic sciences. Teachers and students from around the world would often travelled to study under his guidance. Based in a remote village in Mauritania, he trained hundreds if not thousands of scholars, including Shaykh Hamza Yusuf. He was married with Maryam Bint Muhammad al-Amin Ould Muhammad Ahmad Bwayba who died 12 April 2009. In 2016, he was selected by The Royal Islamic Strategic Studies Centre amongst 'The 500 Most Influential Muslims'.
Murabit al-Hajj died in his home village Tuwamarat, Mauritania on 17 July 2018 at the age of 105 years. He was the cousin of Sheikh Muhammad al-Hassan Walid al-Dido al-Shanqiti, the head of the northwest African country's Center for the Development of Scholars. Murabit al-Hajj is currently oldest known man from Mauritania.