Kvarnbäcken is a settlement in Piteå Municipality, in Norrbotten County, Sweden. It has 53 inhabitants. The nearest city is Piteå, 12.7 km to the southeast. Beaches nearby: Räkan (11 km). Among the landmarks around are Piteå City Church (12.8 km), Öjeby Church (7.9 km) and Hortlax Church (14.3 km).