Home Postcode finder SA Hamilton Hamilton postcode SA Hamilton is a locality in South Australia covered by postcode 5373. Postcode 5373 State or territory South Australia (SA) Region Sa Subs Near 1 Add a free Hamilton business listing Be the first listing in Hamilton Common questionsWhat is the postcode for Hamilton?Hamilton, SA has the postcode 5373.What state is Hamilton in?Hamilton is in South Australia (SA).Does postcode 5373 cover more than one suburb?Yes. Postcode 5373 covers 8 localities, so the postcode alone does not identify Hamilton. Browse other postcodes in South Australia, or widen the search to every Australian postcode.