group of Romance dialects spoken in Switzerland and northern Italy. The most important Rhaetian dialects are Sursilvan and Sutsilvan, which together make up the Romansh language (q.v.). Other Rhaetian dialects are Engadine, spoken in Switzerland in the Inn River valley; Ladin, spoken in the Alto Adige and Dolomites regions of northern Italy; and Friulian, spoken north of Venice to the Austrian border and east to the Yugoslavian border.

The Swiss Rhaetian dialects seem to resemble French more than any other Romance language, whereas Ladin and Friulian are more similar to Italian. The two groups are not closely related and appear to have developed independently of one another.