Brunei was once under Japanese occupation.

The Japanese invaded Brunei on December 16, 1941, eight days after the attack on Pearl Harbor. The Japanese attacked and conquered Brunei with the hopes of obtaining a portion of the country's oil. Despite Brunei's protectorate status, the British did not intervene.

The Japanese embraced indirect rule, with native leaders serving as military government instruments based on their previous standing and abilities. Japanese was taught in schools under the Japanese occupation, and government personnel were compelled to take night lessons to master the language. The Japanese also attempted to incite anti-European feeling among Bruneians.

The final days of Japanese rule were characterised by severe food and medical supply shortages. The Japanese occupied Brunei for over three and a half years until being driven out by victorious Allied forces led by Australian Forces in June 1945.