Semlin is a village in the administrative district of Gmina Zblewo, within Starogard County, Pomeranian Voivodeship, in northern Poland. It lies approximately 7 km north-east of Zblewo, 10 km west of Starogard Gdański, and 46 km south of the regional capital Gdańsk. It is located within the ethnocultural region of Kociewie in the historic region of Pomerania. Semlin was a royal village of the Polish Crown, administratively located in the Tczew County in the Pomeranian Voivodeship.