Tynset 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 Tynset.The municipality (originally the parish) is named after the old Tynset farm (Old Norse: Tunnusetr), since the first church was built here. The first element is the genitive case of the river name Tunna (now Tonna); the last element derives from setr which means "homestead" or "farm". (The meaning of the river name is unknown.) Prior to 1918, the name was written "Tønset" (pronounced Teunset, the diphthong equivalent to that in the French: bleu).