Home Postcode finder NSW Gillieston Heights Gillieston Heights postcode NSW Gillieston Heights is a locality in New South Wales covered by postcode 2321. Postcode 2321 State or territory New South Wales (NSW) Region Hunter Add a free Gillieston Heights business listing More business listings in Gillieston Heights Businesses in Gillieston HeightsGillieston Public SchoolSchool Lane · 02 49327542 Common questionsWhat is the postcode for Gillieston Heights?Gillieston Heights, NSW has the postcode 2321.What state is Gillieston Heights in?Gillieston Heights is in New South Wales (NSW).Does postcode 2321 cover more than one suburb?Yes. Postcode 2321 covers 20 localities, so the postcode alone does not identify Gillieston Heights. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.