Southern Tsimshian, Sgüüx̣s or Ski:xs, is the southern dialect of the Tsimshian language, spoken by the Gitga'ata and Kitasoo Tsimshians in Klemtu, B.C.. It became extinct with the death of the last remaining speaker, Violet Neasloss.
Sgüüx̣s has been described as a highly conservative dialect of Coast Tsimshian. The name Sgüüx̣s means "the language beside."
Several articles on the language were written by Tsimshian specialist John Asher Dunn.
The language is currently being documented with the goal of being able to create new fluent speakers at some time in the future.