Brunei English (similar and related to British English) is a regional dialect of English that is widely spoken in Brunei Darussalam, even though the national language is Malay. Although the lingua franca in the country is generally the local dialect of Malay, all educated people are proficient in English, as it has been the medium of instruction from the fourth year of primary school since 1985.

There are various features that make Brunei English distinct: for pronunciation, the sound at the start of a word such as three is often [t] rather than [θ], and there is usually a full vowel rather than [ə] in function words such as as, than, and of; for grammar, furnitures and jewelleries are treated as plural nouns, and there is variable use of the third-person −s suffix on present-tense verbs; and for lexis, many words are borrowed from Malay to reflect local customs, including titah (a speech by the Sultan) and tudung (a head scarf). Some of these features are shared with other varieties of Southeast Asian English, but others make Brunei English a distinct variety.

Colloquial portmanteau words for Brunei English are 'Brulish' (recorded from 2003) and 'Brunglish' (recorded from 2007).

Brunei was a British protectorate from 1888 until it became independent in 1984, when it joined ASEAN. English became widely used, even though Brunei Malay (a dialect of Malay that is substantially different from Standard Malay) continues to be the main language that is spoken.

In 1985, the Bilingual Education Policy was implemented, with Malay as the medium of instruction for the first three years of primary school, and then English as the medium of instruction for most subjects from the fourth year of primary school on. In 1993, history switched from being English-medium to being Malay-medium.

In January 2009, a new education policy was implemented. It is termed SPN21 (Sistem Pendidikan Negara – Abad 21, 'National Education System for the 21st Century'). In this new system, mathematics and science are taught in English from the start of primary school.

English is well-established in Brunei, though it does not seem to be challenging the position of Malay. Rather more threatened are the minority languages such as Dusun (Dusun Brunei), Tutong and Murut (Lun Bawang), which seem to be getting squeezed out by the two dominant languages, though recent research in Temburong District suggests that Murut is surviving better than the other two.

There is substantial variation in the English spoken in Brunei. Two sources of variation are mentioned here: education and ethnicity.