Uthman ibn Affan, the third Caliph of Islam, sent the first official Muslim envoy to Vietnam and Tang Dynasty China in 650. Seafaring Arab traders are known to have made stops at ports in the Champa Kingdom en route to China very early in the history of Islam; however, the earliest material evidence of the transmission of Islam consists of Song Dynasty-era documents from China which record that the Cham familiarised themselves with Islam in the late 10th and early 11th centuries. The number of followers began to increase as contacts with Sultanate of Malacca broadened in the wake of the 1471 collapse of the Champa Kingdom, but Islam would not become widespread among the Cham until the mid-17th century. In the mid-19th century, many Muslim Chams emigrated from Cambodia and settled in the Mekong River Delta region, further bolstering the presence of Islam in Vietnam. Malayan Islam began to have an increasing influence on the Chams in the early 20th century; religions publications were imported from Malaya, Malay clerics gave khutba (sermons) in mosques in the Malay language, and some Cham people went to Malayan madrasah to further their studies of Islam.
After the 1976 establishment of the Socialist Republic of Vietnam, some of the 55,000 Muslim Chams emigrated to Malaysia. 1,750 were also accepted as immigrants by Yemen; most settled in Ta’izz. Those who remained did not suffer violent persecution, although some writers claim that their mosques were closed by the government. In 1981, foreign visitors to Vietnam were still permitted to speak to indigenous Muslims and pray alongside them, and a 1985 account described Ho Chi Minh City’s Muslim community as being especially ethnically diverse: aside from Cham people, there were also Indonesians, Malays, Pakistanis, Yemenis, Omanis, and North Africans; their total numbers were roughly 10,000 at the time. However, Vietnam’s Muslims remained relatively isolated from the mainstream of world Islam, and their isolation, combined with the lack of religious schools, caused the practice of Islam in Vietnam to become increasingly syncretic.
Vietnam’s largest mosque was opened in January 2006 in Xuan Loc, Dong Nai Province; its construction was partially funded by donations from Saudi Arabia.