The Wieprz (Polish: [ˈvjɛpʂ], lit. '"Boar"'; Ukrainian: Вепр, romanized: Vepr) is a river in central-eastern Poland, a tributary of the Vistula. It is the country's ninth longest river, with a total length of 349 km and a catchment area of 10,497 km2, all within Poland. Its course near the town of Łęczna includes the protected area known as Wieprz Landscape Park.