Kota Belud gained its name from the combination of two words in Bajau language.

[1] In the past before the existence of a government body, there was often hostility between the races of different villages in the area.

Hence, the Bajaus have chosen a hill as their fortress which subsequently known as "Kota Belud".

[1] According to the last census in 2010, the population of Kota Belud district is estimated to be around 91,27,[2] mainly Bajau (including Illanun) people and also Dusun (Tindal and Tobilung tribes).

As in other districts of Sabah, there are a significant number of illegal immigrants from the nearby southern Philippines, mainly from the Sulu Archipelago and Mindanao, many of whom are not included in the population statistics.