Home Postcode finder SA Cadell Lagoon Cadell Lagoon postcode SA Cadell Lagoon is a locality in South Australia covered by postcode 5321. Postcode 5321 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Cadell Lagoon business listing Be the first listing in Cadell Lagoon Common questionsWhat is the postcode for Cadell Lagoon?Cadell Lagoon, SA has the postcode 5321.What state is Cadell Lagoon in?Cadell Lagoon is in South Australia (SA).Does postcode 5321 cover more than one suburb?Yes. Postcode 5321 covers 2 localities, so the postcode alone does not identify Cadell Lagoon. Browse other postcodes in South Australia, or widen the search to every Australian postcode.