Prey depletion poses a threat to large carnivores worldwide. The Javan leopard (Panthera pardus melas), the last remaining apex predator on the Indonesian island of Java, is facing numerous threats from human activities including poaching, habitat loss and prey depletion. Despite the fact that the Javan leopard is an adaptable and opportunistic predator capable of surviving in various environments, our understanding of its prey and predator-prey interactions is still limited, which is crucial for their conservation. Using camera trap data collected from four national parks (i.e., Ujung Kulon, Gunung Gede Pangrango, Meru Betiri, Alas Purwo) that represent four distinct terrestrial ecoregions across the island of Java, we investigated the species richness, relative abundance, and spatial-temporal overlap in activity patterns between the Javan leopard and other animals that coexist in the same location. Our analysis of 7461 independent photos, covering 12,983 camera trap days, revealed that areas with the presence of Javan leopards exhibited higher species richness and abundance compared to those without the presence of Javan leopards. In addition, we found that the activities of banteng (Bos javanicus), barking deer (Muntiacus muntjak), Javan deer (Rusa timorensis), Javan mousedeer (Tragulus javanicus), wild boar (Sus scrofa), junglefowl (Gallus spp.), spangled ebony langur (Trachypithecus auratus), Javan rhino (Rhinoceros sondaicus), long-tailed macaque (Macaca fascicularis) and dhole (Cuon alpinus) were highly overlapping with those of Javan leopards in space and time, suggesting that these species are potential candidate prey for Javan leopards. To our knowledge, this is the first comprehensive investigation of potential prey for the Javan leopard that utilizes camera traps from all four types of terrestrial ecoregions on Java Island. The findings of this study may serve as essential information for the conservation of this critically endangered species.