Peist is a former municipality in the district of Plessur in the canton of Graubünden in Switzerland . On 1 January 2013 the former municipalities of Peist, Calfreisen , Castiel, Langwies , Lüen , Molinis and St. Peter-Pagig merged into the municipality of Arosa .

Peist is first mentioned in 1084 as de Paiste.

Before the merger, Peist had a total area of 17.9 km2 (6.9 sq mi). Of this area, 57% is used for agricultural purposes, while 35.7% is forested.