Lundu is a district, in Kuching Division, Sarawak, Malaysia. It is divided into Sematan subdistrict and Lundu, its district seat.

There is no recent census that related about residents population based on religion in Lundu District area. However, according to a survey by Ministry of Public Health, Housing and Local Government (MPHLG) Sarawak in early 2024, Islam dominates the population in Lundu District with total around 13,905 residents, followed by Christianity (with total 9,280 residents), and some other minority religions.