The name Marudu originated from the language of Balangigi people from the words of "Mairudu" or "Maiuludu" which means "a position located in the same place", referring to the geographical position of Marudu Bay which forms a large bay.

While in the waters of Marudu, he found the Balangigi people or also called by the Spaniards as the "Camucones"[note 1] became the sea troops of the Sultanates of Brunei and Sulu at the time.

[2] He later involved in a dispute with the colonial authorities of British North Borneo after being accused as a pirate and involved in a slave trade, where he was killed during a battle with the latter and his entire fort in the area was destroyed.

[4] It consists mainly of Dusun (from the Gobukon, Tobilung, Tagahas, Bunduliwan-Tinagas, Kimaragang-Sonsogon, Garo, Luba and Talantang tribes), Rungus, Bajau, Orang Sungai (Tambanuo) and Chinese (mainly Hakkas).

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