Alvdal is a municipality in Hedmark county, Norway. It is part of the traditional region of Østerdalen. The administrative centre of the municipality is the village of Alvdal. Alvdal (along with the eastern part of Folldal municipality) was separated from the municipality of Tynset to become a municipality of its own in 1864. The western part of Folldal was transferred from Dovre (in Oppland county) to Alvdal (and Hedmark county) in 1884.