Słupsk [swupsk] ( listen) (German: Stolp, Kashubian: Stôłpsk or Słëpsk, Latin: Stolpa) is a city in the Pomeranian Voivodeship, in the northern part of Poland. Before 1 January 1999, it was the capital of the separate Słupsk Voivodeship. It is also a part of the historic region of Pomerania.

The city is located in the northwestern part of the country, on the Slovincian Coast, 18 kilometres (11 mi) from the Baltic Sea on the Słupia River. It is the administrative seat of Słupsk County, although it is not part of that county (the city has county status in its own right). It has a population of 98,757 and occupies 43.15 square kilometres (16.66 sq mi), being one of the most densely populated cities in the country according to the Central Statistical Office. The neighbouring administrative districts (gminas) are Gmina Kobylnica and Gmina Słupsk. There is ongoing discussion regarding extension of the city boundaries to include some territory belonging to those two gminas.

Słupsk had its origins as a Slavic Pomeranian settlement on the Słupia river in early Middle Ages, which later became part of Piast Poland. In 1265 it was given city rights. By the 14th century, the town had become a centre of local administration and trade and a Hanseatic League associate. Between 1368 and 1478, it was the residence of the Dukes of Pomerania. In 1648, according to the peace treaty of Osnabrück, Słupsk became part of Brandenburg-Prussia. In 1815 it was incorporated into the newly formed Province of Pomerania. The city became part of the People's Republic of Poland in 1945.