T
- T. B. Irving - An American scholar, author and translator
- Tariq Abdul-Wahad (Olivier Saint-Jean) - originally from France, former basketball player for the Mavericks and Kings[142]
- Tawana Brawley (changed her name to Maryam Muhammad) - African American woman noted for claiming to have been raped by several white men, a claim determined to be a fabrication by a grand jury. Later in life she converted to Islam.[143][144][145]
- Tekuder - Mongol leader of the Ilkhan empire who was formerly a Nestorian Christian.[146]
- Thomas J. Abercrombie - photographer[147]
- Timothy Winter - prominent British Islamic thinker and scholar, and a lecturer in Islamic studies in the Faculty of Divinity at the University of Cambridge.[148]
- Torquato Cardilli - Italian ambassador, converted From Catholicism.[149]
- Vincenzo Luvineri - American rapper and the lyricist behind the Philadelphia underground hip-hop group Jedi Mind Tricks, converted From Catholicism.[150]
- Wadih el-Hage born to a Maronite Christian family in Sidon, Lebanon, a former al-Qaeda member.[citation needed]
- William Abdullah Quilliam - 19th century British poet, ambassador and journalist.[151]
- Willie Brigitte - French convert to Islam who associated with al-Qaeda in Pakistan and was possibly involved in a plot to conduct a terrorist operation in Australia.[152]
- Yousuf Youhana - prolific Pakistani cricketer, who converted from Christianity to Islam and became Muhamed Yousuf
- Yahiya Emerick - American Muslim scholar, President of the Islamic Foundation of North America, converted from Protestantism.[153]
- Yasin Abu Bakr (Lennox Philip) - of Trinidad and Tobago, under trial for an attempted coup as of 9 March 2006[154]
- Yusuf Estes - Former preacher and federal prison chaplain, converted from Protestantism.[155]
- Yvonne Ridley - British journalist, from Anglicanism. She converted after being kidnapped and released by the Taliban.[156][157]
- Zaid Shakir - American Muslim convert former Baptist, speaker, intellectual, author, and resident scholar of Zaytuna Institute in the United States.[158][159]
- Zağanos Pasha - one of the prominent military commanders of Mehmet II (Mehmet the Conqueror) and a lala, at once an advisor, mentor, tutor, councillor, protector, for the sultan.[160]
