Hazimism, also referred to as the Hazimi movement or known as the Hazimiyyah or Hazimi current, is a movement within the ideology of Islamic State. The movement was derived from the doctrines of the Saudi-born Muslim scholar Ahmad ibn Umar al-Hazimi, which was adopted by many Tunisian recruits within ISIS.

Hazimis believe that those who do not unconditionally excommunicate (takfir) unbelievers are themselves unbelievers, which opponents argue leads to an unending chain of takfir. Its spread within ISIS triggered prolonged ideological conflict within the group, pitting its followers against the moderate faction led by Turki al-Binali. It has been described as "ultra-extreme" and "even more extreme than ISIS". The movement was eventually branded as extremist by ISIS, who initiated a crackdown on its followers.

Due to al-Hazimi's reluctance to directly comment on the subject of politics, there exist varying beliefs among the Hazimi movement, leading some to argue that it does not present itself as a unique manhaj. Hazimis spans from direct Salafi-jihadist elements currently aligned with Boko Haram and formerly associated with ISIS, to those hesitating to explicitly criticise the Saudi monarchy. Hazimis regard participation in the democratic system or process as grounds for takfir and a nullifier of Islam, considering it equivalent to prostration to an idol.

Contemporary Salafi-Jihadi movements base their beliefs on the teachings of theologian Muhammad ibn Abd al-Wahhab. However, al-Hazimi asserted that the doctrines put forward by contemporary Salafi-jihadi thinkers were not to be blindly followed, challenging the consensual authority of Ibn Taymiyyah. This outlook would completely shake the ideological foundations of the Salafi-jihadi movement. Hazimi's doctrines were also highly influenced by the doctrines of the Egyptian militant Islamist ideologue Sayyid Qutb.

Central to Hazimism is the doctrine of takfir al-'adhir ("excommunication of the excuser"). In his treatise Nullifiers of Islam, Muhammad ibn Abd al-Wahhab writes that those who do not excommunicate (takfir) unbelievers are themselves, unbelievers, whether that is because they doubt their disbelief (kufr) or otherwise. Hazimism differs from mainline Wahabbism by rejecting the concept of al-'udhr bi'l-jahl ("excusing on the basis of ignorance"), which asserts that those who doubt the disbelief of a disbeliever due to their own ignorance are not disbelievers. This concept is considered by jihadis to be a restraint on excessive takfir.

To justify their claims, various Hazimi ideologues assert that Ibn Taymiyyah was against the principle of al-'udhr bi'l-jahl in affairs of shirk (polytheism). Al-Hazimi categorically rejects al-'udhr bi'l-jahl for actions he considers to be of "greater polytheism" (al-shirk al-akbar) and "greater disbelief" (al-kufr al-akbar), such as voting in elections and supplicating to the dead. Al-Hazimi states that those who refuse to pronounce takfir on the performers of such actions on the basis of al-'udhr bi'l-jahl are themselves unbelievers.

Between December 2011 and May 2012, al-Hazimi delivered four lectures in Tunisia. He was supported by the Islamic Good Society and Hay al-Khadra' Mosques Committee. While the members of the former were arrested for financing terrorism, the latter had maintained links to Ansar al-Sharia in Tunisia (AST). With the aid of the committee, al-Hazimi founded the Ibn Abi Zayd al-Qayrawani Institute for Sharia Sciences, which promoted his teachings. His views were also amplified through AST's Facebook page.

In the following years, several Tunisians who adopted al-Hazimi's views joined ISIS. During the group's conflict with the al-Nusra Front, the Tunisians remained loyal and were rewarded with senior administrative and religious posts. With increasing influence, however, their belief in takfir al-'adhir (excommunication of the excuser) became a source of concern for ISIS leadership. Bahraini scholar Turki al-Binali, who led the group's Office of Research and Studies, prepared a series of lectures and pamphlets against the doctrine. He argued that while al-'udhr bi'l-jahl was invalid in instances of greater polytheism and disbelief, this does not necessarily mean that those who make excuses are disbelievers. In a tweet, he also described the belief as bidʻah (religious innovation). The Binalis, as they were later termed, also claimed the Hazimi view led to an "infinite regress of takfir" (al-takfir bi'l-tasalsul).