Ahmed Husein Deedat (Gujarati: અહમદ હુસેન દીદત; Urdu: احمد حسین دیدات; Arabic: أحمد حسين ديدات; 1 July 1918 – 8 August 2005), was a South African and Indian self-taught Muslim thinker, author, and orator on Comparative Religion. He was best known as a Muslim missionary, who held numerous inter-religious public debates with evangelical Christians, as well as video lectures on Islam, Christianity, and the Bible.

Deedat established the IPCI, an international Islamic missionary organisation, and wrote several widely distributed booklets on Islam and Christianity. He was awarded the King Faisal International Prize in 1986 for his fifty years of missionary work. He wrote and lectured in English.