Gmina Kętrzyn is a rural gmina (administrative district) in Kętrzyn County, Warmian-Masurian Voivodeship, in northern Poland. Its seat is the town of Kętrzyn, although the town is not part of the territory of the gmina.

The gmina covers an area of 285.73 square kilometres (110.3 sq mi), and as of 2006 its total population is 8,285.

Gmina Kętrzyn contains the villages and settlements of:

Gmina Kętrzyn is bordered by the town of Kętrzyn and by the gminas of Barciany, Giżycko, Korsze, Mrągowo, Reszel, Ryn, Srokowo and Węgorzewo.

• Polish official population figures 2006