The East Carpathian Biosphere Reserve is a transboundary protected area, designated as an area of global importance under UNESCO's Programme on Man and the Biosphere.
It is located in the Eastern Carpathians and includes parts of three countries: Poland, Slovakia and Ukraine.
The Biosphere reserve covers a total area of 2,132.11 square kilometres (823.21 sq mi).
The reserve was originally designated as a Polish–Slovak transboundary reserve in 1992; it was extended to include the Ukrainian part in 1998.
It includes the following national protected areas:
- In Poland
- Bieszczady National Park (Bieszczadzki Park Narodowy) and the two neighbouring landscape parks called Cisna-Wetlina Landscape Park (Ciśniańsko-Wetliński Park Krajobrazowy) and San Valley Landscape Park (Park Krajobrazowy Doliny Sanu);
- In Slovakia
- Poloniny National Park (Národný park Poloniny) and adjacent areas;
- In Ukraine
- National Nature Park of Uzh River (Національний природний парк Ужанський) and the Trans-San (Nadsyansky) Regional Landscape Park.