Gmina Jasień is an urban-rural gmina (administrative district) in Żary County, Lubusz Voivodeship, in western Poland. Its seat is the town of Jasień, which lies approximately 16 kilometres (10 mi) north-west of Żary and 40 km (25 mi) south-west of Zielona Góra.
The gmina covers an area of 127.02 square kilometres (49.0 sq mi), and as of 2019 its total population was 7,040.