Home Postcode finder QLD Llanarth Llanarth postcode QLD Llanarth is a locality in Queensland covered by postcode 4820. Postcode 4820 State or territory Queensland (QLD) Region North QLD Add a free Llanarth business listing Be the first listing in Llanarth Common questionsWhat is the postcode for Llanarth?Llanarth, QLD has the postcode 4820.What state is Llanarth in?Llanarth is in Queensland (QLD).Does postcode 4820 cover more than one suburb?Yes. Postcode 4820 covers 21 localities, so the postcode alone does not identify Llanarth. Browse other postcodes in Queensland, or widen the search to every Australian postcode.