Trysil is a municipality in Innlandet county, Norway. It is located in the traditional district of Østerdalen. The administrative centre of the municipality is the village of Innbygda. Other villages in the municipality include Nybergsund, Østby, and Tørberget.

Innlandet is a county in Norway. It was created on 1 January 2020 with the merger of the old counties of Oppland and Hedmark. The new county has an area of 52,113 square kilometres (20,121 sq mi), making it the largest county in Norway after Troms og Finnmark was split up in 2024.