Lierne National Park (Norwegian: Lierne nasjonalpark) lies in the municipality of Lierne in Nord-Trøndelag county, Norway. The park was established on 17 December 2004 by a royal resolution. The park covers 333 square kilometres (129 sq mi) of land along the border with Sweden.
The park is dominated by a large mountainous region rich in lynx, wolverines, bears, and wildfowl. The rare Arctic fox also live in the area. Much of the land was formed during the last Ice Age. There are many peaks over 1,000 metres (3,300 ft) above sea level, the highest of which is Hestkjøltopp at 1,390 metres (4,560 ft). There are many wetland areas with large swamps and open woodlands.