Duvin (German: Duvin ), Romansh: Duin ) is a former municipality in the district of Surselva in the Swiss canton of Graubünden. On 1 January 2014 the former municipalities of Duvin, Castrisch , Ilanz, Ladir , Luven , Pitasch , Riein , Ruschein , Schnaus , Sevgein , Pigniu , Rueun and Siat merged into the new municipality of Ilanz/Glion .

Duvin is first mentioned about 840 as Auna. In 1290 it was mentioned as Aiuns.

Before the merger, Duvin had a total area of 17.9 km2 (6.9 sq mi). Of this area, 22% is used for agricultural purposes, while 40% is forested.