Bytów (; is a town in the Middle Pomerania region of northern Poland in the Bytów Lakeland with 16,888 inhabitants (2004). Previously in Słupsk Voivodeship (1975–1998), it is the capital of Bytów County in Pomeranian Voivodeship (since 1999).
According to the city's official webpage the name Bytów comes from the founder of the settlement named "Byt". An old Pomeranian settlement was first mentioned by Latin name castrum nomine Bitom in 1113 in Gallus Anonymus' Chronicle, as conquered by Polish king Bolesław III Wrymouth. In 1321 the city was mentioned as "Butow" when it became private possession of the noble family von Behr, who sold it to the Teutonic Knights in 1329. In 1346 the Grand Master Heinrich Dusemer granted Bütow city rights under Kulm Law. The Teutonic Knights had started in 1335 with the construction of a rectory. The town alternated between Poland and the Monastic state of the Teutonic Knights during the Polish-Teutonic Wars, and returned to Polish control after the Second Peace of Thorn (1466), who gave it as lien to the Dukes of Pomerania. The final legal situation of Bytów was regulated in 1526
In 1627 during the Thirty Years' War, the town was rebuilt after being destroyed by a fire. Between 1627 and 1657 Bytów ceased to be a Polish fief and became directly ruled by Poland. To gain an ally against Sweden during the Deluge, in 1657 King John II Casimir of Poland gave the Lauenburg and Bütow Land to Margrave Frederick William of Brandenburg-Prussia as a hereditary fief in the Treaty of Bydgoszcz. Although Poland still retained sovereignty, the town was administered by Brandenburg and, after 1701, by the Kingdom of Prussia. During the 18th century, the town suffered from fires and plague.
In 1773 in the First Partition of Poland the town was wholly incorporated in the Prussian Province of Pomerania. From 1846-1945, Bütow was the seat of the Landkreis Bütow district in Prussia. The town became part of the German Empire in 1871 during the Prussian-led unification of Germany. Polish minority remained active in the city, and in 1910 a Polish Bank Ludowy was founded here.
Although reconstituted Poland desired Bütow at the end of World War I, the Treaty of Versailles kept the town in the Weimar Republic in 1919. The decision led the local Kashubians to protests and hundreds of them took part in march known as "marsz na Bytów".
According to Polish sources (published in 1969) The area remained the main centre of activity by Polish minority in the region and in 1923 Związek Polaków na obszar Kaszubski was founded in the city In 1928 Jan Bauer, a Polish teacher organised Polish language lessons, and reinvigorated the Polish movement in the city, which resulted in repressions by German state, and his eventual conviction and exile from Germany in 1932. Finding himself at the outbreak of Second World War in Berlin he was arrested and murdered by Nazis in 1940.
Bütow was occupied by the Soviet Red Army on 8 March 1945. In 1945, after the end of the war, the town was put under Polish administration according to the Potsdam Conference and renamed to the Polish Bytów. Its German inhabitants were expelled and replaced with Poles, mainly from Polish areas annexed by the Soviet Union.
Bytów became the seat of a powiat (1946–1975, 1999-) within Poland.
Up to the end of World War II most inhabitants of the town were Protestants.