Rhaeto-Romance, Rheto-Romance, Rhaeto-Italian,or Rhaetian, is a purported subfamily of the Romance languages that is spoken in south-eastern Switzerland and north-eastern Italy. The name "Rhaeto-Romance" refers to the former Roman province of Raetia. The question of whether these languages actually form a subfamily is called the Questione Ladina. The Italian linguist Graziadio Ascoli, writing in 1873, found them to share a number of intricacies and believed they formed a linguistic group. The Rhaeto-Romance languages differ from Italian in their evolution from Latin by having passed through a stage with phonemic vowel length, undergone certain consonant developments, and possibly developed a pair of central rounded vowels. If the subfamily is genuine, three languages would belong to it: Romansh in Switzerland, and Ladin and Friulian in Italy. Their combined number of speakers is about 660,000; the large majority of these speak Friulian.

Romansh is a Gallo-Romance language spoken predominantly in the Swiss canton of the Grisons (Graubünden). Romansh has been recognized as a national language of Switzerland since 1938, and as an official language in correspondence with Romansh-speaking citizens since 1996, along with German, French, and Italian. It also has official status in the canton of the Grisons alongside German and Italian and is used as the medium of instruction in schools in Romansh-speaking areas. It is sometimes grouped by linguists with Ladin and Friulian as the Rhaeto-Romance languages, though this is disputed.