Home Postcode finder QLD Hyde Park Castletown Hyde Park Castletown postcode QLD Hyde Park Castletown is a locality in Queensland covered by postcode 4812. Postcode 4812 State or territory Queensland (QLD) Region North QLD Add a free Hyde Park Castletown business listing Be the first listing in Hyde Park Castletown Common questionsWhat is the postcode for Hyde Park Castletown?Hyde Park Castletown, QLD has the postcode 4812.What state is Hyde Park Castletown in?Hyde Park Castletown is in Queensland (QLD).Does postcode 4812 cover more than one suburb?Yes. Postcode 4812 covers 9 localities, so the postcode alone does not identify Hyde Park Castletown. Browse other postcodes in Queensland, or widen the search to every Australian postcode.