We examine the relationship between socio-economic disadvantage and exposure to environmental hazard with data from the catastrophic 2019–2020 Australian wildfires (Black Summer) that burnt at least 19 million hectares, thousands of buildings and was responsible for the deaths of 34 people and more than one billion animals. Combining data from the National Indicative Aggregated Fire Extent (NIAFE) and 2016 Socio-Economic Indexes for Areas (SEIFA), we estimate the correlation between wildfire hazard exposure and an index of community-level socio-economic disadvantage. Wildfire hazard exposure is measured as the interaction between the percentage of area burnt and proximity of the fire to settlements. The results reveal a significant positive relationship between fire hazard exposure and socio-economic disadvantage, such that the most socio-economically disadvantaged communities bore a disproportionately higher hazard exposure in the Black Summer than relatively advantaged communities. Our spatial analysis shows that the socio-economic disadvantage and wildfire hazard exposure relationship exists in inner regional, outer regional and remote areas of New South Wales and Victoria, the two worst-hit states of the Black Summer catastrophe. Our spatial analysis also finds that wildfire hazard exposure, even within a small geographical area, vary substantially depending on the socio-economic profiles of communities. A possible explanation for our findings is resource gaps for fire suppression and hazard reduction that favour communities with a greater level of socio-economic advantage.