Gacyny [ɡaˈt͡sɨnɨ] is a settlement in the administrative district of Gmina Wejherowo, within Wejherowo County, Pomeranian Voivodeship, in northern Poland. It lies approximately 12 kilometres (7 mi) south-east of Wejherowo and 25 km (16 mi) north-west of the regional capital Gdańsk.

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