Sępólno County (powiat sępoleński) is a unit of territorial administration and local government (powiat) in Kuyavian-Pomeranian Voivodeship, north-central Poland. It came into being on January 1, 1999, as a result of the Polish local government reforms passed in 1998. Its administrative seat and largest town is Sępólno Krajeńskie, which lies 49 km north-west of Bydgoszcz and 86 km north-west of Toruń. The county also contains the towns of Więcbork, lying 11 km south of Sępólno Krajeńskie, and Kamień Krajeński, 10 km north of Sępólno Krajeńskie.
The county covers an area of 790.86 km2. As of 2019 its total population is 41,055, out of which the population of Sępólno Krajeńskie is 9,091, that of Więcbork is 5,950, that of Kamień Krajeński is 2,390, and the rural population is 23,624.
Sępólno County is bordered by Człuchów County and Chojnice County to the north, Tuchola County to the north-east, Bydgoszcz County to the south-east, Nakło County to the south, and Piła County and Złotów County to the west.
