Home Postcode finder QLD Cosgrove Cosgrove postcode QLD Cosgrove is a locality in Queensland covered by postcode 4818. Postcode 4818 State or territory Queensland (QLD) Region North QLD Add a free Cosgrove business listing Be the first listing in Cosgrove Common questionsWhat is the postcode for Cosgrove?Cosgrove, QLD has the postcode 4818.What state is Cosgrove in?Cosgrove is in Queensland (QLD).Does postcode 4818 cover more than one suburb?Yes. Postcode 4818 covers 18 localities, so the postcode alone does not identify Cosgrove. Browse other postcodes in Queensland, or widen the search to every Australian postcode.