Gmina Wieleń is an urban-rural gmina in Czarnków-Trzcianka County, Greater Poland Voivodeship, in west-central Poland. Its seat is the town of Wieleń, which lies approximately 27 kilometres west of Czarnków and 75 km north-west of the regional capital Poznań. The gmina covers an area of 428.32 square kilometres, and as of 2006 its total population is 12,572.