Infectious disease is an emerging driver of mortality for marine megafauna, yet predicting disease risk remains challenging due to limited integration of behavioural and epidemiological processes. This study combines social network analysis and epidemiological modelling to assess disease vulnerability across multiple populations of Australian inshore dolphins. Using standardised network metrics across species and sites, we quantify variation in social structure and simulate disease spread using network-based epidemic models. Results reveal substantial differences in epidemic probability and outbreak size both within and between species, likely influenced by population-specific patterns of connectivity, organisation, and ecological context. These findings suggest that disease vulnerability cannot be inferred from species identity alone but emerges from the interaction between social structure and local ecological conditions. Incorporating these dynamics into conservation planning provides a framework to identify high-risk populations and prioritise targeted, evidence-based management strategies to enhance resilience in vulnerable marine megafauna.