West Attica (Greek: Δυτική Αττική) is one of the regional units of Greece.

The regional unit covers the western part of the agglomeration of Athens, and the area to its west.

The regional unit West Attica is subdivided into 5 municipalities.

As a part of the 2011 Kallikratis government reform, the regional unit West Attica was created out of the former prefecture West Attica (Greek: νομαρχία Δυτικής Αττικής).

The prefecture had the same territory as the present regional unit.