With the arrival of Arab traders in the 7th century A.D., Islam began to flourish in Sri Lanka. The first people to profess the Islamic faith were Arab merchants and their native wives, whom they married after having them converted to Islam. By the 8th century A.D., Arab traders had controlled much of the trade on the Indian Ocean, including that of Sri Lanka. Many of them settled down on the island in large numbers, encouraging the spread of Islam. However, when the Portuguese arrived during the 16th century, many of their descendants now called the Sri Lankan Moors were mainly traders and merchants with spice trading networks spanning to the Middle East. The Portuguese colonists attacked, persecuted and destroyed the Sri Lankan Moor settlements, warehouses and trading networks. Many defeated Moors refugees escaped from the persecution to the interior in central Sri Lanka. The population of Sri Lankan Moors significantly declined during the Portuguese colonial rule due to the pograms against the Moors. The Sinhalese ruler King Senarat of Kandy gave refuge to some of the Muslims in the central highlands and Eastern Province, Sri Lanka.
During 18th and 19th centuries, Javanese and Malaysian Muslims bought over by the Dutch and British rulers contributed to the growing Muslim population in Sri Lanka. Their descendants, now the Sri Lankan Malays, adapted several Sri Lankan Moor Islamic traditions while also contributing their unique cultural Islamic practices to other Muslim groups on the Island.
The arrival of Muslims from India during the 19th and 20th centuries has also contributed to the growth of Islam in Sri Lanka. Most notably, Pakistani and South Indian Muslims have introduced Shafi’i and the Hanafi school of thought into Sri Lanka, however although most Muslims on the island still adhere to the traditional practices of Sunni Islam and Fassiyatush Shadhiliyya Sufi order.
Muslims generally follow Sunni Sufi traditions like Mawlid, Tawassul and Dhikr. Ummu zavaya at M.J.M.Laffir mawatha stands as the headquarters of Fassiyatush Shazuliya Sufi order which is widely practiced all over the country. Sufi Dawat-e-Islami and Deobandi Tablighi Jamaat too have centers in Colombo. Sunni scholar Muhammad Abdul Aleem Siddiqi built Hanafi Masjid in Colombo for Sri Lankan Muslims.
In 2012, Sri Lankan government ordered 161 foreign Tablighi Jamaat preachers to leave the country for flouting visa regulations. Local Muslims had complained that the visitors were not teaching a moderate form of Islam.
In modern times, Muslims in Sri Lanka are handled by the Muslim Religious and Cultural Affairs Department, which was established in the 1980s to prevent the continual isolation of the Muslim community from the rest of Sri Lanka. Muslims of Sri Lanka, mostly from the Moor and Malay ethnic communities on the island with smaller numbers of converts from other ethnicities, such as the Tamils.