Home Postcode finder NSW Guyong Guyong postcode NSW Guyong is a locality in New South Wales covered by postcode 2798. Postcode 2798 State or territory New South Wales (NSW) Region NSW Country West Add a free Guyong business listing Be the first listing in Guyong Common questionsWhat is the postcode for Guyong?Guyong, NSW has the postcode 2798.What state is Guyong in?Guyong is in New South Wales (NSW).Does postcode 2798 cover more than one suburb?Yes. Postcode 2798 covers 5 localities, so the postcode alone does not identify Guyong. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.