Islam is the most common religion in the Indonesian province of West Sumatra, embraced by 97.42% of the population. The Muslim population increases to 99.6% if it excludes the Mentawai Islands, where the majority of the non-Muslim (Protestant) West Sumatrans reside. Islam in West Sumatra is predominantly Sunni, though there is a small Shia Islamic pocket within the coastal city of Pariaman. The Minangkabau people, indigenous to West Sumatra, comprise 88% of the West Sumatran population today and have historically played an important role within Indonesia's Muslim community. Up until today, the region is considered one of the strongholds of Islam in Indonesia.

The introduction of Islam in the West Sumatran region, especially the Minangkabau Highlands, the home of the Minangkabau people, is assumed to have taken two routes: one from eastern Minangkabau between the 7th and 8th centuries, and another from the west coast of Minangkabau after the 16th century. The first route was cultivated by the Muslim Arab traders who came down from the Strait of Malacca through the Kampar River, flowing from the highlands into the strait. This trading activity is estimated as the first contact between the indigenous people and Islam.

The cultural contact became more intensive in the 13th century with the rise of the Muslim Samudera Pasai Sultanate in the northern Sumatra, assuming control of the strait and advancing into east Minangkabau for gold mines and pepper production centers. After the Strait of Malacca fell into Portuguese hands during the 16th century, Islam began entering the west coast of Minangkabau through coastal cities such as Pariaman.

The most substantial Muslim empire in the region was Aceh Sultanate, based in the current Aceh province. Intensive interactions between the Aceh Sultanate and Minangkabau region had developed into significant influence by the former on the latter in terms of Islamic teachings. Among the first Islamic proselytizers in the Minangkabau area was Sheikh Burhanuddin Ulakan, a disciple of Sheikh Abdur Rauf Singkil, who adhered to the Acehnese line of Shattari tariqa. Shattari tariqa quickly spread into Minangkabau through the traditional religious educational institution known as surau.

Islam began to be established in many port towns along the coasts of West Sumatra around the 16th century. The earliest to adopt the religion were the ruling elites and local merchants, although proselytization among the rest of society eventually occurred during the 18th century. Once Islam spread into the interior, the locals accommodated the religion with the ancient customs and culture of the Minangkabau.

Islam was propagated by several Sufi orders, namely Shattari and Naqshbandi tariqas, through surau and proselytization in the 17th to 19th centuries. There were specific differences in the way religion had developed between the western coastal area and the eastern inland area during the process. The more syncretic form of Islam was spread within the inland area through Naqshbandi tariqa. This Sufi sect was disseminated by Ismail al-Khalidi al-Minangkabawi, and gained a strong foothold there, combined with the commercial advantage coming from its geographic proximity to the Strait of Malacca.

The development of Islam in West Sumatra can also be characterized by tasawwuf (the science of Islamic mysticism) through the emphasis on sharia, which was instituted by the influential Minangkabau ulamas, pioneered by Tuanku Nan Tuo. Tuanku Nan Tuo was a Sufi-oriented reformer who took a wasatiyyah (moderate) position; his syncretic approach between the orthodoxy and non-orthodoxy had successfully laid the foundation of sharia within the Minangkabau Sufi traditions. This led to the comprehensive development of Islamic sciences and studies, often accompanied by applying Islamic solutions to social issues and otherworldly affairs, not confining it to the spiritual aspects.

This development had attempted to transform various aspects of Minangkabau society, especially within the inland agrarian area. The transformation was often colored by conflicts in the religious interpretations stemming from the cultural roots of the Minangkabau people, such as the matriarchal system. The conflict, for example, between the mainstream sharia and Naqshbandi practices, as well as later Islamic modernism between the Sufi orders, had resulted in the intense intellectual development of the religious interpretations and indirectly contributed to the ascendance of the Minangkabau region as one of the most important centers in the history of Islam in Indonesia.