Pisz (pronounced Peesh [pʲiʂ], previously also Jańsbork, German: Johannisburg; Masurian: Jánsbork) is a historic town in the Warmian-Masurian Voivodeship in northern Poland, with a population of 19,466 (2016).

The name Pisz originates from the word pisa, meaning "swamp" in the ancient Prussian language, owing to the muddy water from nearby Lake Roś.

In 1345 the Teutonic Order began constructing a castle nearby at the southernmost point of the Piska Forest, in the Masurian Lake District.

[5] Its early growth owed much to the residents' skill in beekeeping, and it was located on trade routes leading to Gdańsk and to the Vistula and Narew Rivers.

In 1698, King of Poland Augustus II the Strong and Elector of Brandenburg Frederick I held a meeting in the local castle.

At war's end in 1945, it was transferred from German to Polish control according to the Potsdam Agreement and officially renamed Pisz in 1946.

The name Pisz comes from the Old Prussian word pisa ("swamp"), owing to the muddy water from nearby Lake Roś.

Historic sites of Pisz include the Gothic town hall, the Church of St. John, the ruins of the Teutonic Knights' castle and preserved World War II bunkers.

Due to natural resources comprising the reach forestry and shallow deposits of bog iron ore, the industrial traditions of Pisz are connected with wood processing (the sawmill) and metallurgy.

[4] Pisz is a centre of tourism industry, with boat trips, canoeing and kayaking along the Krutynia River, as well as with popular yachting voyages on the Masurian Lakes known in Polish as Kraina Wielkich Jezior.