A preliminary genome sequence has been assembled for the Southern Ocean salp, Salpa thompsoni (Urochordata, Thaliacea). Despite the ecological importance of the species in Antarctic pelagic food webs and its potential role as an indicator of changing Southern Ocean ecosystems in response to climate change, no genomic resources are available for S. thompsoni, nor any closely related urochordate species. Using a multiple-platform, multiple-individual approach, we have produced the first reference genome sequence for S. thompsoni. This reference includes protein predictions associated with Gene Ontology functional information, SNP variant and 9,782 indeed predictions, serving as a resource for future phylogenomic and population genetic studies. Moreover, we performed an initial survey of small RNAs, including miRNAs and piRNAs. Collectively, these resources provide a genomic foundation supporting S. thompsoni as a model species for studying urochordate evolution, impacts of complex life histories and reproductive modes, polar marine biology and genetic effects of climate change on key species in the fragile and endangered Antarctic pelagic ecosystem.