Lierne National Park is located in the municipality, and Blåfjella-Skjækerfjella National Park is partly located in Lierne.
Lierne is also home to many lakes, including Gusvatnet, Havdalsvatnet, Holden, Ingelsvatnet, Kingen, Kvesjøen, Laksjøen, Lenglingen, Limingen, Murusjøen, Rengen, Sandsjøen, Stortissvatnet, Tunnsjøen, and Ulen.