Home Postcode finder SA Cavenagh Cavenagh postcode SA Cavenagh is a locality in South Australia covered by postcode 5422. Postcode 5422 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Cavenagh business listing Be the first listing in Cavenagh Common questionsWhat is the postcode for Cavenagh?Cavenagh, SA has the postcode 5422.What state is Cavenagh in?Cavenagh is in South Australia (SA).Does postcode 5422 cover more than one suburb?Yes. Postcode 5422 covers 13 localities, so the postcode alone does not identify Cavenagh. Browse other postcodes in South Australia, or widen the search to every Australian postcode.