Gmina Siemień is a rural gmina (administrative district) in Parczew County, Lublin Voivodeship, in eastern Poland. Its seat is the village of Siemień, which lies approximately 7 kilometres (4 mi) west of Parczew and 45 km (28 mi) north of the regional capital Lublin.
The gmina covers an area of 110.93 square kilometres (42.8 sq mi), and as of 2006 its total population is 4,825 (4,712 in 2014).