Pygmy blue whales are listed as Endangered and their distribution and areas of high use overlap with proposed offshore renewable energy (ORE) development areas in Australia. To assess the level of overlap and potential impacts, quantification of the relative importance of the areas they use across their distribution in relation to spatial data on pressures is required. We did this using satellite tracking data and complemented it with other data sources (surveys, habitat models). The relative pygmy blue whale distribution was overlaid with spatial data of pressures (existing shipping and oil-gas activity, and proposed ORE) and associated threats (habitat loss, displacement, vessel strike, underwater noise) in a cumulative impact assessment framework. An impact score was calculated using the spatial overlap between the whale occupancy with the intensity of each threat weighted by the species’ vulnerability to it. The cumulative impact score was then calculated and mapped across the species distribution. We also identified areas of low impact that can act as potential control sites for ORE monitoring programs. Our outputs quantifying the potential impacts of ORE in addition to the existing anthropogenic activities will assist government, regulators, and proponents in assessing and mitigating impacts of ORE developments to this species.