In Islam, a Maturidi (Arabic: ماتريدي) is one who follows Abu Mansur Al Maturidi's systematic theology (kalam), which is close to the Ash'ari theology. The school is known as Maturidism or Maturidiyyah. It is considered one of the orthodox theologies in Sunni Islam alongside the Ash'ari school. Many Turkic tribes and Asian Muslims practice Maturidism.
Points about which the Maturidis differ from the Ash'aris are, among others, the nature of belief and the place of human reason. The Maturidis state that iman (faith) does not increase nor decrease with actions; it is rather taqwa (piety) which increases and decreases. The Ash'aris say that belief does in fact increase and decrease according to the taqwa.
Regarding the increased emphasis placed on the role of human reason, the Maturidis say that the unaided human mind is able to find out that the more major sins such as alcohol or murder are immoral and evil without the aid of revelation. The Ash'aris disagree, and conclude that the unaided human mind is unable to determine if something is good or evil, lawful or unlawful, moral or immoral, without the direct aid of divine revelation. Another point where Ash'aris and Maturidis differ regarding the role of human reason is divine amnesty for certain non-Muslims in the afterlife.
Both the Ash'aris and Maturidis follow occasionalism, a philosophy which refutes the basis for causality, but also proves the existence and nature of the Islamic belief of the tawhid (oneness of God) through formal logic.
This theology is popular where the Hanafi school of law is followed, particularly the lands of the former Turkic Ottoman and Mughal empires, viz. in Turkey, Tatarstan, Bashkortostan, the Balkans, the Caucasus, the Levant, Afghanistan, Central Asia, northwest China, Pakistan, Bangladesh, and India.