Expansive urban, industrial, and agricultural development along the Australian coastline has led to increased pollution of the marine environment by a wide variety of anthropogenic chemicals. The potentially detrimental impact of these chemicals on marine megafauna is of concern, due to their susceptibility to bioaccumulation and biomagnification. This study has undertaken a comprehensive compilation of the published data for trace metal concentrations in Australian marine mammals, birds, and turtles. Most studies relied on the utilisation of opportunistically collected samples, animal strandings, and bycatch. Large data gaps in geographical, temporal and species coverage were found. For instance, there is little or no data for cetaceans in NSW or NT and the WA data comprises mainly mercury data for over 400 sperm whales captured in the 1970s. Where possible, trends in the data were examined including comparisons with international data. There was a lack of supporting diagnostic data on dead and stranded animals to account for the cause of mortality or identify physiologic changes that may result from exposure to contaminants (e.g., compromised renal function and Cd exposure). The key knowledge gaps, trends, and recommendations for future investigations will be presented.