Fire regimes are shifting around the world due to climate and land-use change, resulting in an increased frequency of large and severe wildfires. However, the impact of extreme wildfire events on animal species remains poorly understood. Particularly lacking is an understanding of how fire affects animal behaviour. By examining how distinct vertebrate groups respond to wildfire, we capture variations in resilience mechanisms that further our understanding of fire ecology and aid conservation strategies in increasingly fire-prone landscapes. Across an area of 180 110 ha, we investigated the effects of the 2019–2020 Australian wildfires on vegetation structure (a proxy for vertebrate habitat), the number of independent detections (as an indicator of abundance), and diel activity of a range of terrestrial animals in eucalypt forests of south-eastern Australia. We examined the influence of fire severity on vegetation structure, using wildlife cameras, animal species abundance, and how burnt or unburnt areas and fire severity affect species' diel activity patterns 20 months post-fire. Areas subject to high severity fires (in comparison to low and moderate severity) had less canopy cover and leaf litter, and higher vegetation cover at measured (0 to > 2 m) understory heights, as well as greater abundance of logs. Fire severity had a limited effect on the abundance of animal species, with differences in abundance observed in eight of 29 species. Greater impact occurred following high severity fire, where 8/29 species were affected, compared to 3/29 in areas burnt at low and moderate severity. However, only 4/29 species (high severity) and 1/29 (low and moderate severity) responded negatively, demonstrating a general resilience among many species to fire. Areas that burnt at high severity had higher introduced mammal richness and reduced native mammal diversity, suggesting the potential for introduced species to establish in severely burnt areas. The diel activity patterns in areas subject to fire differed for seven of 17 species with sufficient data, with these species concentrating their activity during specific times in burnt areas compared to unburnt areas. Such behavioural plasticity may facilitate species persistence in environments modified by fire by allowing species to exploit different resources or minimise predation risk. Understanding how fire affects animal species, including animal behaviour, will be critical as the world's fire regimes continue to change.