Its administrative seat and largest town is Ciechanów, which lies  north of Warsaw. The only other town in the county is Glinojeck, lying  west of Ciechanów.
Ciechanów 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.