Trysil is a municipality in Innlandet county, Norway. It is part of the traditional region of Østerdalen. The administrative centre of the municipality is the village of Innbygda. The municipality of Trysil was established on 1 January 1838 (see formannskapsdistrikt).

The municipality (originally the parish) is probably named after an old farm - and this was most likely the original name of Prestgarden ("the vicarage"), where the first church was built. The meaning of the first element is unknown (maybe an old river name), the last element is sil which means "quiet stretch of a river". Prior to 1906, the name was spelled "Tryssil".

Trysil is a great place to explore the Norwegian nature and participating in various outdoor activities like guided trips, river fishing, dog sledge driving, elk safari, night photography, stargazing. This includes a mountain at Norway's largest ski resort, which offers many of the country's most widely acclaimed downhill and slalom slopes.