Siedlce County () is a unit of territorial administration and local government (powiat) in Masovian Voivodeship, east-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 is the city of Siedlce, although the city is not part of the county (it constitutes a separate city county). The only town in Siedlce County is Mordy, which lies east of Siedlce.
The county covers an area of . As of 2019 its total population is 81,265, out of which the population of Mordy is 1,788 and the rural population is 79,477.
Apart from the city of Siedlce, Siedlce County is also bordered by WÃÂgrów County and Sokoà Âów County to the north, Siemiatycze County to the north-east, à Âosice County and Biaà Âa County to the east, à Âuków County to the south, Garwolin County to the south-west, and Mià Âsk County to the west.
The county is subdivided into 13 gminas (one urban-rural and 12 rural). These are listed in the following table, in descending order of population.