Wizna Land (Polish: ziemia wiska), named after the town of Wizna, was an administrative unit (ziemia) of the Duchy of Mazovia, Kingdom of Poland and the Polish-Lithuanian Commonwealth. With its capital in Wizna, it belonged to Masovian Voivodeship. In the 16th century, Wizna Land was divided into two counties: Wizna (area 555 km2) and Wasosz (area 863 km2). The total area of Wizna Land was 1419 km2, with 280 villages.