The Torre Valley dialect or Ter Valley dialect (tersko narečje,terščina) is the westernmost and the most Romanized Slovene dialect and one of its most archaic and typologically interesting dialects. It is spoken mostly in the Torre Valley in the Province of Udine in Italy, in the northern part of the historical region known as Venetian Slovenia, and in some villages in western Slovenia. It belongs to the Littoral dialect group. Historically, it included the village of Pers (Slovene: Breg or Brieh), the westernmost ethnically Slovene village.
The dialect was written already in the Cividale manuscript in 1479, but was later not used in written form. Nowadays, because of the lack of language policy and Italianization, the dialect has a very reduced number of speakers and is threatened with extinction. The Italian municipalities of Taipana and Lusevera and the village of Breginj in Slovenia are the only areas where the dialect is still maintained. In 2009, a dictionary of the Torre Valley dialect was published, based on material collected mainly at the end of the 19th century, but also in the 20th century.
The Torre Valley dialect is spoken in the mountainous area of eastern Friuli, along the upper course of the Torre River to west of the Natisone River, in the historical region known as Venetian Slovenia. It is located south of the Resian and Soča dialect, and west of the Natisone Valley dialect. To the east, it is bordered by Friulian.