The Warsaw West County (Polish: powiat warszawski zachodni) is a county in Masovian Voivodeship, located in the east-central Poland, with its seat of government located in Ożarów Mazowiecki.

Other towns located in the county are: Łomianki, and Błonie.

It was established on January 1, 1999, as a result of the Polish local government reforms.

Until 31 December 2005, its seat was located extraterritorially in the city of Warsaw.

The county covers an area of 532.99 square kilometres (205.8 sq mi).