The Treaty of Kępno was an agreement between the High Duke of Poland and Wielkopolska Przemysł II and the Duke of Pomerania Mestwin II signed on February 15, 1282, which transferred the suzerainty over Gdańsk Pomerania (Pomeralia) to Przemysł. As a result of the treaty Przemysł adopted the title dux Polonie et Pomeranie.

Przemysł II was the Duke of Poznań from 1257–1279, of Greater Poland from 1279 to 1296, of Kraków from 1290 to 1291, and Gdańsk Pomerania (Pomerelia) from 1294 to 1296, and then King of Poland from 1295 until his death. After a long period of Polish high dukes and two nominal kings, he was the first to obtain the hereditary title of king, and thus to return Poland to the rank of kingdom. A member of the Greater Poland branch of the House of Piast as the only son of Duke Przemysł I and the Silesian Princess Elisabeth, he was born posthumously; for this reason he was brought up at the court of his uncle Bolesław the Pious and received his own district to rule, the Duchy of Poznań in 1273. Six years later, after the death of his uncle, he also obtained the Duchy of Kalisz.