The Dzierżęcinka [ipa: /d͡ʑjɛrʐɛ̃t͡ɕiŋka/]' (German: Mühlenbach) is a river in Poland with a length of 29.30 km, located in Koszalin County in the West Pomeranian Voivodeship. Rising in nearby Manowo, the Dzierżęcinka flows through Koszalin and eventually reaches Jamno lagoon to the north.