Rex Seán O'Fahey (1943 – April 9, 2019) was an Irish historian specializing in Islamic Africa.
[3] O'Fahey also helped found the Institute for the Study of Islamic Thought in Africa at Northwestern.
[3] He also maintained close relations with the Sudanese National Records Office, whose long-term director, Muhammad Ibrahim Abu Salim, he once described as his "mentor.
His later research moved eastwards towards the central Sudan, and focused on Sufism, a major force in Sudanese life and society.
[4] His work on Sufism and the Sudan was taken further by a number of his PhD students, including Anders Bjørkelo, Ali Salih Karrar, Knut S. Vikør, Endre Stiansen, Albrecht Hofheinz, Anne K. Bang, and Mark Sedgwick.