Eukaryotic microbes resident in the mammalians gut have an important role in maintaining metabolism, in the digestion of nutrients, and in the regulation of the immune system. Therefore, changes in the composition of the microbial in gut may generate adverse impacts on animal health. In the present study, the faecal eukaryotic community obtained from young Arctocephalus australis (n =1) and A. tropicalis (n = 4) was investigated using high-throughput sequencing. The results showed that the Eukaryotic community in the seals’ feces mainly was consisted of the class Chordata (42.96%), Chromadorea (23.93%), Trematoda (11.74%), Maxillopoda (5.23%), Cephalopoda (1.16%), and other class of micro-eukaryotes not yet reported in fecal samples of pinnipeds found in South America. This study provides new insight into the fecal eukaryotic community of wild young South American and Subantarctic fur seals and confirms the high-throughput sequencing technology as a tool to more broadly define gut biodiversity.