Marine mammals have been used globally as sentinels for ecosystem health, with numerous threatening processes increasing conservation concern. Amongst these threats is the exposure to toxicants, documented to be greater for coastal species who inhabit waters closer to the point source of contamination, thus more likely to have higher body burdens. Currently there is limited knowledge on the toxicant threat and burdens for marine mammals in costal Victorian waters, making it difficult to manage or mitigate this threat. Here we provide the trace element and organic pollutant contaminant body burden in multiple tissues of six marine mammal species from Victorian coastal and inshore waterways. Three dolphin species; Burrunan dolphin (Tursiops australis), short-beaked common dolphin (Delphinus delphis), and the common bottlenose dolphin (Tursiops truncatus), and three pinniped species; Australian fur seal (Arctocephalus pusillus doriferus), long-nosed fur seal (Arctocephalus forsteri), and the sub-Antarctic fur seal (Arctocephalus tropicalis). This is the first time a multi-taxa, multi tissue analysis has been conducted to investigate the toxicant exposure on a broad range of contaminants within marine mammals the region.