Home Postcode finder SA Johnburgh Johnburgh postcode SA Johnburgh is a locality in South Australia covered by postcode 5431. Postcode 5431 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Johnburgh business listing Be the first listing in Johnburgh Common questionsWhat is the postcode for Johnburgh?Johnburgh, SA has the postcode 5431.What state is Johnburgh in?Johnburgh is in South Australia (SA).Does postcode 5431 cover more than one suburb?Yes. Postcode 5431 covers 14 localities, so the postcode alone does not identify Johnburgh. Browse other postcodes in South Australia, or widen the search to every Australian postcode.