Home Postcode finder SA Seaton Seaton postcode SA Seaton is a locality in South Australia covered by postcode 5023. Postcode 5023 State or territory South Australia (SA) Region Adelaide Add a free Seaton business listing More business listings in Seaton Businesses in SeatonEnviro Roofing1 Clark Terrace · 1300 85 05 04JML DecoratingSeaton South Australia 5023, Australia · 0451855800MC Property Plus1 Clark Terrace, Seaton SA 5023, Australia · 0404 431 780 Common questionsWhat is the postcode for Seaton?Seaton, SA has the postcode 5023.What state is Seaton in?Seaton is in South Australia (SA).Does postcode 5023 cover more than one suburb?Yes. Postcode 5023 covers 3 localities, so the postcode alone does not identify Seaton. Browse other postcodes in South Australia, or widen the search to every Australian postcode.