Gmina Mielno is an urban-rural gmina (administrative district) in Koszalin County, West Pomeranian Voivodeship, in north-western Poland. Its seat is the village of Mielno, a resort on the Baltic Sea coast.

The gmina covers an area of 62.54 square kilometres (24.1 sq mi), and as of 2006 its total population is 5,068.

Gmina Mielno contains the villages and settlements of Barnowo, Chłopy, Czajcze, Gąski, Komorniki, Łazy, Mielenko, Mielenko-Kolonia, Mielno, Niegoszcz, Paprotno, Pękalin, Radzichowo, Sarbinowo and Unieście.

Gmina Mielno is bordered by the gminas of Będzino, Darłowo and Sianów.

• Polish official population figures 2006