Mierzynek [mjɛˈʐɨnɛk] is a village in the administrative district of Gmina Karlino, within Białogard County, West Pomeranian Voivodeship, in north-western Poland. It lies approximately 11 kilometres (7 mi) north of Karlino, 16 km (10 mi) north of Białogard, and 118 km (73 mi) north-east of the regional capital Szczecin.

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