Marine Cloud Brightening (MCB) is a proposed solar radiation management technique for reducing the impact of marine heatwave conditions on coral reefs (Harrison 2019). Coral reefs, such as Australia’s Great Barrier Reef (GBR), are highly susceptible to marine heatwaves, with marine heatwaves causing several mass coral bleaching events on the GBR in recent years (Hughes 2021). In this hydrodynamic-biogeochemical modelling study we sought to understand the potential spatio-temporal implications of MCB scenarios on coral bleaching outcomes. We used CSIRO’s ‘eReefs’ environmental modelling suite in hindcast to examine the oceanographic response to a range of assumed cloud albedo forcing scenarios over contemporary mass bleaching events. The scenarios explored differing assumed effectiveness and spatial extent of radiative forcing. We found that the unique oceanography of the GBR exerts a strong influence on the spatial distribution of potential bleaching mitigation. Our results suggest that regionally targeted MCB may lower implementation costs while only marginally reducing benefits.