Kuala Belait (KB; Jawi: کوالا بلايت‎) is the administrative town of Belait District, Brunei. The population of the town proper was 4,259 in 2016. Kuala Belait is officially a municipal area (kawasan bandaran), as well as a village under the mukim of the same name. The town is located 85 kilometres (53 mi) west of the country's capital Bandar Seri Begawan, and 20 kilometres (12 mi) west of Seria, the district's other town. It is also in the westernmost part of country, near the mouth of the Belait River.