The Bremer River is a river that is a tributary of the Brisbane River, located in the Scenic Rim and Brisbane regions of South East Queensland, Australia. The 100-kilometre (62 mi)-long Bremer River drains several Scenic Rim valleys in south-east Queensland, including the Fassifern Valley, with its catchment area covering approximately 2,032 square kilometres (785 sq mi). Most valleys within the catchment have extensive river terraces. The Bremer River system is extremely degraded.

The Brisbane River is the longest river in South East Queensland, Australia, and flows through the city of Brisbane, before emptying into Moreton Bay on the Coral Sea. John Oxley, the first European to explore the river, named it after the Governor of New South Wales, Sir Thomas Brisbane in 1823. The penal colony of Moreton Bay later adopted the same name, eventually becoming the present city of Brisbane. The river is a tidal estuary and the water is brackish from its mouth through the majority of the Brisbane metropolitan area westward to the Mount Crosby Weir. The river is wide and navigable throughout the Brisbane metropolitan area.