Pierwoszyno [pjɛrvɔˈʂɨnɔ] is a village in the administrative district of Gmina Kosakowo, within Puck County, Pomeranian Voivodeship, in northern Poland. It lies approximately 2 kilometres (1.2 mi) north-east of Kosakowo, 14 kilometres (8.7 mi) south-east of Puck, and 27 kilometres (17 mi) north of the regional capital Gdańsk.

For details of the history of the region, see History of Pomerania.