Rheinwald is a municipality in the Viamala Region in the Swiss canton of the Grisons . On 1 January 2019 the former municipalities of Hinterrhein, Nufenen and Splügen merged to form the new municipality of Rheinwald.

Hinterrhein is first mentioned in 1219 as de Reno.

Nufenen was first mentioned in 1343 as Ovena. In 1633 it was mentioned as Nufena. In Romansh it was known as Nueinas and it used to be known as Novena in Italian.