Gmina Sępólno Krajeńskie is an urban-rural gmina in Sępólno County, Kuyavian-Pomeranian Voivodeship, in north-central Poland. Its seat in the historic Krajna region is the town of Sępólno Krajeńskie, which lies approximately 49 kilometres north-west of Bydgoszcz. The gmina covers an area of 229.18 square kilometres, and as of 2006 its total population is 15,907. The gmina contains part of the protected area called Krajna Landscape Park.