It is located east of Bandar Seri Begawan, Brunei.

It is the ocean gateway to the isolated Temburong District of Brunei, separated from the rest of Brunei by the Malaysian Sarawak State surrounding it to the bay.

[1] Brunei Bay contains some 8,000 hectares of tidal mudflats and sandflats, seagrass beds, coral reefs, mangroves, beach forest and sandstone islets.

These have been identified by BirdLife International as an Important Bird Area (IBA) because it supports significant numbers of the populations of various bird species, including Bonaparte's nightjars, lesser adjutants, Storm's storks, Chinese egrets, greater sandplovers, spotted greenshanks and roseate terns.

Threats include inshore trawling, waterbird hunting, and habitat fragmentation through mangrove clearance.