The religious movement known as the Wahhābīyah, sometimes anglicized as “Wahhabism,” is founded on the teachings of Muḥammad Ibn ῾Abd al‐Wahhāb (1703–1791), who wrote on a variety of Islamic subjects such as theology, exegesis, jurisprudence, and the life of the prophet Muḥammad. A set of issues dominated the teachings of Muḥammad Ibn ῾Abd al‐Wahhāb and distinguished the Wahhābīyah from other Islamic movements. These include tawḥīd (the unity of God), tawassul (intercession), ziyārat al‐qubūr (visitation of graves and erection of tombs), takfīr (charge of unbelief), bid῾ah (innovation), and ijtihād and taqlīd (original juristic opinions and imitation of tradition).

Tawḥīd is the central theme in the Wahhābī doctrine; Ibn ῾Abd al‐Wahhāb considered it the religion of Islam in itself. He maintained that the unity of God reveals itself in three distinct manners. The first is tawḥīd al‐rubūbīyah, the assertion of the unity of God and his action: God alone is the creator, provider, and disposer of the universe. The second is tawḥīd al‐asmā' wa‐al‐ṣifāt (unity of names and attributes), which deals with God's characteristics. “God is the Beneficent, the Merciful, … the Knowledgeable. He is established on the Throne, and unto Him belongeth whatsoever is in the heavens and whatsoever is in the earth, and whatsoever is between them, and whatsoever is beneath the sod” (Qur'ān, surah 20.6). The third aspect, tawhīd al‐Ilāhīyah, prescribes that worship should be to God alone. The assertion that “there is no god but Allāh and Muḥammad is the Prophet of God” means that all forms of worship should be devoted solely to God; Muḥammad is not to be worshiped, but, as an apostle, he should be obeyed and followed.

The Wahhābīs strongly disagreed with their opponents on the question of tawassul (intercession). For Muḥammad Ibn ῾Abd al‐Wahhāb, ῾ibādah (worship) refers to all the utterances and actions—inward as well as outward—that God desires and commands. He wrote that to seek protection from trees, stones, and the like is polytheistic, nor are aid, protection, or refuge to be sought from anyone except God. Intercession cannot be granted without God's permission and his satisfaction with the one for whom it is asked, who must be a true monotheist. The common practice of seeking intercession from dead saints is prohibited, as is excessive devotion at their tombs. Invoking the Prophet to intercede for individuals before God is also unacceptable, because the Prophet was neither able to guide those he liked to Islam without the will of God nor was he allowed to ask forgiveness from God for polytheists.

The doctrine of intercession led the Wahhābīs to denounce vehemently the widely followed practice of visitation of tombs and the building of domes near them. Initially Ibn ῾Abd al‐Wahhāb had considered visitation, if performed in the true spirit of Islam, a pious and praiseworthy act. However, Wahhābīs believe that people have transformed the prayers for the dead into prayers to the dead; gravesites became places of assembly for worshipers. The excessive veneration of the deceased who enjoyed a holy reputation was a first step that had led people to idol‐worship in the past. To avoid polytheism, the Wahhābīs consider it an obligation to destroy all such existing tombs. They insist that burial sites should be level with the ground and that inscriptions, decoration, or illumination of graves should be avoided. The Wahhābīs also believe that mere affiliation with Islam is not sufficient in itself to prevent a Muslim from becoming a polytheist. The person who utters the Shahādah and still practices polytheism (as defined by the Wahhābīs) should be denounced as an infidel and killed.

Innovation (bid῾ah) is another Wahhābī concern. It is defined as any doctrine or action not based on the Qur'ān, the traditions, or the authority of the Prophet's companions. Ibn ῾Abd al‐Wahhāb condemned all forms of innovation and rejected the views of those who maintained that an innovation could be good or praiseworthy. He invoked the authority of the Qur'ān and the traditions of Muḥammad to support his views. The Wahhābīs rejected as bid῾ah such acts as celebrating the Prophet's birthday, seeking intercession from saints, reciting the Fatīḥah on behalf of the founders of Ṣūfī orders after the five daily prayers, and repeating the five daily prayers after the final Friday prayer in the month of Ramaḋān.

The conflict of ijtihād and taqlīd is the sixth principal concern. According to Ibn ῾Abd al‐Wahhāb and his followers, God commanded people to obey him alone and to follow the teachings of the Prophet. This complete adherence to the Qur'ān and the traditions that Wahhābīs demanded of Muslims also entailed a rejection of all interpretations offered by the four schools of Islamic jurisprudence—including the Wahhābīs' own Ḥanbalī school where it is not in accordance with the two prime sources.

The Wahhābīs developed strict procedures to direct the discussion of doctrinal issues. To judge religious questions, they first search the texts of the Qur'ān and the ḥadīths and define their views accordingly. If reference is not found in these texts, they look for the consensus of the “Virtuous Ancestors,” particularly the companions and their successors, and the ijmā῾ (consensus) of scholars; ijmā῾, however, is restricted to those who follow the Qur'ān and the traditions.

The Wahhābīs reject the idea that the doors of ijtihād are closed. Although they follow the Ḥanbalī school, they do not accept its precepts as final. If any Ḥanbalī interpretation can be proven wrong, then it must be abandoned. In support of their argument, the Wahhābīs quote Qur'ānic verses that imply that the Qur'an and the traditions constitute the only bases of Islamic law.

The Wahhābīyah became the dominant religious and political force in the Arabian Peninsula around 1746, when the Āl Sa῾ūd combined their political force with Wahhābī teachings. One principality after another fell under the attacks of the Saudi forces. In 1773 the Principality of Riyadh fell and its properties were incorporated by the treasury of al‐Dir῾īyah, the seat of the Āl Sa῾ūd and the Wahhābīs. With the fall of Riyadh a new order was established in the peninsula, ushering the period of the first Saudi state and establishing the Wahhābīyah as the strongest religio‐political force in the Arabian Peninsula during the nineteenth and early twentieth centuries. Today many of the Wahhābī principles guide the legal and social life of the Kingdom of Saudi Arabia.