Patterns and processes of catchment disturbance, connectivity, and transfer of sediment to waterways from hillslopes and floodplains following bushfires and floods are poorly understood in eastern Australia. Fires cause biophysical alterations to vegetation and soils, leading to changes in infiltration, runoff, and erosion potential when heavy rainfall occurs. These factors may compound at the scale of a river reach due to the interaction of broader, catchment-scale processes with local fire and flood impacts. Saturated floodplain conditions, loss of riparian vegetation and associated roughness, and rapidly changing river levels can lead to bank erosion and slumping which may be key modes of geomorphic adjustment. This was documented using satellite imagery, photogrammetry and field observations in a partly-confined reach of the Tuross River on the south coast of NSW following the 2019/20 Australian ‘Black Summer’ bushfires and subsequent 2020 and 2021 floods. Mass failure of a ~200 m section of riverbank and subsequent bank retreat and floodplain erosion liberated an estimated ~6,600 m3 (~9,950 t) of sediment directly to the river. This represents a significant enhancement in sediment supply to this reach, and also to the lower Tuross River sediment budget overall. Subsequent revetment works largely stabilised the bank, limiting channel expansion. While the fate of the eroded sediment is unknown, it likely contributed to deleterious impacts on downstream water quality, aquatic processes and habitats in the system, which are important considerations for river and estuary management.