Sallirmiutun (formerly Siglitun) is the dialect of Inuvialuktun spoken by the Siglit, an Inuit group of the Northwest Territories, Canada. It is mainly used in the Inuvialuit communities of Paulatuk, Sachs Harbour and Tuktoyaktuk. Sallirmiutun was once the principal dialect of the Mackenzie River delta, nearby parts of the coast and Arctic Ocean islands, but the number of speakers fell dramatically following outbreaks of new diseases in the 19th century and for many years Sallirmiutun was believed to be completely extinct. It was only in the 1980s that outsiders realised that it was still spoken.