Augustów Primeval Forest (Polish: Puszcza Augustowska, Lithuanian: Augustavo giria, Belarusian: Аўгустоўская пушча) is a large virgin forest complex located in Poland as well as in northern Belarus and southeastern Lithuania. The forest covers about 1,600 km², of which 1,140 km² is in Poland.
The Polish part of the forest is located in Podlaskie Voivodeship in northeastern part of the country.
The northern part of the Augustów Primeval Forest has been turned into one of the youngest Polish national parks. It was established in 1989, as the Wigry National Park.