Zambrów County is a unit of territorial administration and local government (powiat) in Podlaskie Voivodeship, north-eastern Poland. It came into being on January 1, 1999, as a result of the Polish local government reforms passed in 1998. Its administrative seat and only town is Zambrów, which lies 64 km west of the regional capital Białystok. The county covers an area of 733.11 km2. As of 2019 its total population is 43,663, out of which the population of Zambrów is 22,098 and the rural population is 21,565.

Neighbouring counties

Zambrów County is bordered by Łomża County to the north, Białystok County and Wysokie Mazowieckie County to the east, and Ostrów Mazowiecka County to the south-west.

Administrative division

The county is subdivided into five gminas (one urban and four rural). These are listed in the following table, in descending order of population.