Aukštaitija National Park is a national park in northeastern Lithuania, about 100 km north of Vilnius. Established in 1974, it is the oldest of the five national parks in Lithuania. At first it was named Lithuanian SSR National Park to emphasize that it was the first such park in the republic. In 1991, four other parks were established and were renamed after ethnographic regions of Lithuania. The park was renamed after Aukštaitija.
Park territory occupies 405.7 km². Ignalina district municipality controls about 50% of the area. Utena and Švenčionys district municipalities control 25%. Strictly protected areas occupy 2.1%. One can enter this territory only with accompanying employee of the park. Over 70 percent of its territory is covered by woods. 80 percent of woods are pine stands, some reaching 200 years old.
Sixty-four species of plants, eight species of fungi, and 48 species of birds that are found in the park are included in the Red book of Lithuania. The park is famous for its biodiversity - 59% of all plant species in Lithuania can be found in the park which covers less than 1% of Lithuania's territory.