The village of Leśno first appears in the records for the year 1342, in which Winrich von Kniprode, master of the Teutonic Knights, granted it to one "Dytryk" for services to be rendered. Leśno was a royal village of the Polish Crown, administratively located in the Tuchola County in the Pomeranian Voivodeship. In the late 18th-century Partitions of Poland, Leśno, like all of the surrounding region, was annexed by the Kingdom of Prussia. Following World War I, in 1918, Poland regained independence, and from 1919 to 1939 it was included as a part of the Second Polish Republic. After the German invasion of Poland in 1939 it was part of Reichsgau Danzig-West Prussia. During the German occupation, the Polish resistance organization Gryf Pomorski (English: "Pomeranian Griffin") maintained a radio station named "Budnik" ("Alarm Clock") in the nearby hamlet of Widno.