Kuala Belait (Jawi: ), officially known in Malay as (literally 'Kuala Belait Town'), is a town located in the westernmost part of Brunei, in Belait District. It is the second largest settlement in the country after Bandar Seri Begawan, the capital of Brunei, and functions as the capital for the district. Kuala Belait is officially a municipality (), as well as a village-level subdivision under the mukim or subdistrict of the same name. The postcode for Kuala Belait subdivision is KA1131.