Home Postcode finder WA Gnowellen Gnowellen postcode WA Gnowellen is a locality in Western Australia covered by postcode 6328. Postcode 6328 State or territory Western Australia (WA) Region Wa Subs 2 Gsr Add a free Gnowellen business listing Be the first listing in Gnowellen Common questionsWhat is the postcode for Gnowellen?Gnowellen, WA has the postcode 6328.What state is Gnowellen in?Gnowellen is in Western Australia (WA).Does postcode 6328 cover more than one suburb?Yes. Postcode 6328 covers 8 localities, so the postcode alone does not identify Gnowellen. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.