Beaufort, Malaysia in the context of Kimanis

The Brunei Malay, also called Bruneian Malay (Malay: Bahasa Melayu Brunei; Jawi: بهاس ملايو بروني‎), is the most widely spoken language in Brunei Darussalam and a lingua franca in some parts of Sarawak and Sabah, such as Labuan, Limbang, Lawas, Sipitang, Beaufort, Kuala Penyu and Papar. Though Standard Malay is promoted as the official national language of Brunei, Brunei Malay is socially dominant and it is currently replacing the minority languages of Brunei, including the Dusun and Tutong languages, existing in a diglossic speech, wherein Brunei Malay is commonly used for daily communication, coexisting with the aforementioned regional languages and Malay creoles, and standard Malay used in formal speech; code switching between standard Malay and Brunei Malay is spoken in informal speech as a lingua franca between Malay creoles and regional languages. It is quite similar to Standard Malay to the point of being almost mutually intelligible with it, being about 84% cognate with standard Malay. Standard Malay is usually spoken with Brunei pronunciation.

Sipitang (Malay: Pekan Sipitang) is the capital of the Sipitang District in the Interior Division of Sabah, Malaysia. Its population was estimated to be around 4,298 in 2010. It is the closest town in Sabah to the Sarawak border, and is 44 kilometres south of Beaufort and 144 kilometres south of Kota Kinabalu, the state capital and also is 123 kilometres north of Long Pasia, one of the famous attraction in Sabah.

The Interior Division (Malay: Bahagian Pedalaman) is an administrative division of the state of Sabah, Malaysia. It occupies the southwest portion of Sabah, bordered by the neighbouring state of Sarawak on its west. With an area of 18,298 square kilometres, it covers 24.9% of Sabah's territory and is home to approximately 14.7% of Sabah's total population. The largest town in the Interior Division is Keningau. Other main towns in this division include Beaufort, Kuala Penyu, Sipitang, Tambunan and Tenom.

The coastal parts of the Division are settled mainly by Bisaya, Bruneian Malays and Kedayan, whereas the inland areas to the east of the Crocker Range are mostly settled by various subgroups of the Dusun people. The town of Tambunan is considered to be a major centre of Dusun culture, while Tenom is the largest town in the heartland of the Murut people. The Long Pasia and Long Mio are the gateway to the Lun Bawang/ Lun Dayeh tribes in Sipitang. In addition, there are large numbers of Chinese people in most of the towns, particularly Beaufort, Keningau and Tenom. The majority of the Division's ethnic Chinese residents are of the Hakka subgroup.

The Bisaya are a group of indigenous people from the northwest coast of East Malaysia and Brunei, on the island of Borneo. Their populations are concentrated around the towns of Beaufort and Kuala Penyu in southern Sabah (where they are included under the Kadazan-Dusun group of peoples), Labuan Federal Territory, and in Limbang District of Sarawak (in which they are grouped under the Orang Ulu designation). The Bisaya tribe bears many similarities to the Tatana Dusun tribe, especially in terms of language, as there is a high degree of mutual intelligibility between the two groups. Nowadays, most Bisaya in Sabah are Muslim, while those living in Sarawak are mostly Christians. In Brunei, they are referred to as Dusun, Jati Dusun, and Bisaya.

The Kedayan (also known as Kadayan, Kadaian or Kadyan) are an ethnic group residing in Brunei, Federal Territory of Labuan, southwest of Sabah, and north of Sarawak on the island of Borneo. According to the Language and Literature Bureau of Brunei, the Kedayan language (ISO 639-3: kxd) is spoken by about 30,000 people in Brunei, and it has been claimed that there are a further 46,500 speakers in Sabah and 37,000 in Sarawak. In Sabah, the Kedayan mainly live in the southern districts of Sipitang and Beaufort, where they are counted as a part of the local Malay populace (and they are often considered as Bruneians owing to assimilation as well as mixed marriage factors). Whilst in Sarawak, the Kedayans mostly reside in the towns of Lawas, Limbang and Miri (especially the Subis area).