Invertebrates play crucial roles in ecosystems and represent a significant proportion of global biodiversity. Particularly, in freshwater ecosystems, aquatic invertebrates play a key role in ecosystem structure and function. Many taxa, such as Odonata, Plecoptera, Ephemeroptera, have life cycles that connect aquatic and terrestrial environments. Southern Patagonia is home to invertebrate groups with Gondwanan distribution, as well as relictual species, while the sub-Antarctic region is particularly notable for the high number of endemic aquatic species. However, invertebrates have historically been under-studied, with only sporadic collections dating back to the seventeenth century. Modern efforts have considered expanding our understanding of Southern Patagonian invertebrates, adding hundreds of species and morphospecies, especially of Diptera, Coleoptera, and Arachnida. Despite these advances, Isla de los Estados has remained largely unexplored due to its hazardous coasts and lack of a permanent human population. This chapter provides a comprehensive overview of the aquatic and terrestrial invertebrate fauna on Isla de los Estados, by synthesizing current knowledge and incorporating new findings from recent sampling efforts.