Home Postcode finder SA Ashton Ashton postcode SA Ashton is a locality in South Australia covered by postcode 5137. Postcode 5137 State or territory South Australia (SA) Region Sa Subs Near 2 Add a free Ashton business listing Be the first listing in Ashton Common questionsWhat is the postcode for Ashton?Ashton, SA has the postcode 5137.What state is Ashton in?Ashton is in South Australia (SA).Does postcode 5137 cover more than one suburb?Yes. Postcode 5137 covers 2 localities, so the postcode alone does not identify Ashton. Browse other postcodes in South Australia, or widen the search to every Australian postcode.