Home Postcode finder QLD Gladstone-City Gladstone-City postcode QLD Gladstone-City is a locality in Queensland covered by postcode 4680. Postcode 4680 State or territory Queensland (QLD) Region Central QLD Add a free Gladstone-City business listing Be the first listing in Gladstone-City Common questionsWhat is the postcode for Gladstone-City?Gladstone-City, QLD has the postcode 4680.What state is Gladstone-City in?Gladstone-City is in Queensland (QLD).Does postcode 4680 cover more than one suburb?Yes. Postcode 4680 covers 41 localities, so the postcode alone does not identify Gladstone-City. Browse other postcodes in Queensland, or widen the search to every Australian postcode.