The Grønkjølen Nature Reserve (Norwegian: Grønkjølen naturreservat) is located in Møre og Romsdal and Trøndelag counties in Norway. The reserve is located in the municipalities of Surnadal (in Møre og Romsdal) and Rindal and Heim (in Trøndelag).

The nature reserve covers 332.1 hectares (821 acres) and most of it lies in the municipality of Rindal. The reserve was established in 1996 to protect a large intact marsh area in a mountainous region, according to the conservation regulations.