Romansh (also spelled Romansch, Rumants(c)h, or Romanche; Romansh:  rumantsch (help·info)/ rumauntsch (help·info)/ romontsch (help·info)/rumàntsch; German: Rätoromanisch; Italian: Romancio) is a Rhaeto-Romance language descended from the Vulgar Latin spoken by the Roman era occupiers of the region. It is closely related to French, Occitan, and Lombard, as well as the other Romance languages to a lesser extent. Romansh is one of the four national languages of Switzerland, along with German, French and Italian.

In the 2000 Swiss census, 35,095 people (of which 27,038 in the canton of Grisons) indicated Romansh as the language of "best command", and 61,815 also as a "regularly spoken" language. Spoken by around 0.9% of Switzerland's 7.7 million inhabitants, Romansh is Switzerland's least-used national language in terms of number of speakers and the tenth most spoken language in Switzerland overall.