Zambrów County (Polish: powiat zambrowski) 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 kilometres (40 mi) west of the regional capital Białystok.

The county covers an area of 733.11 square kilometres (283.1 sq mi).

These are listed in the following table, in descending order of population.