Lemmenjoki National Park (Finnish: Lemmenjoen kansallispuisto, Inari Sami: Lemmee aalmuglâšmecci, Northern Sami: Leammi álbmotmeahcci) is situated in area of municipalities of Inari and Kittilä, Lapland, in Northern Finland. It was founded in 1956 and has since been expanded twice. Its total area is 2,850 square kilometres (1,100 sq mi), making it the biggest national park of Finland and one of the largest in Europe.

The park is named after the Lemmenjoki River, an 80 kilometres (50 mi) long river running through it.

The park is partly bordered by the Anárjohka National Park in Norway.

Around 100 people can be seen digging gold in the area in the summer on 40 claims. Most of the people in the park – around 10,000 people per year – are backpackers, though. There are about 60 kilometres (40 mi) marked paths in the national park, and even some bridges and boats are put up for travelers. There are more than ten free wilderness huts in the park and three chargeable, bookable ones.

The gold-digging area contains two small airfields, Martiniiskonpalo (467 m or 1,532 ft) and Keurulainen (about 500 m or 1,600 ft). They can be used for landing or taking off with small propeller planes.

• List of national parks of Finland
• Protected areas of Finland

• Media related to Lemmenjoki National Park at Wikimedia Commons
• Lemmenjoki National Park travel guide from Wikivoyage
• Outdoors.fi – Lemmenjoki National Park
• Samuel Silhberpapier's pictures of Lemmenjoki