Home Postcode finder SA St Kilda St Kilda postcode SA St Kilda is a locality in South Australia covered by postcode 5110. Postcode 5110 State or territory South Australia (SA) Region Sa Subs Near 1 Add a free St Kilda business listing Be the first listing in St Kilda Common questionsWhat is the postcode for St Kilda?St Kilda, SA has the postcode 5110.What state is St Kilda in?St Kilda is in South Australia (SA).Does postcode 5110 cover more than one suburb?Yes. Postcode 5110 covers 6 localities, so the postcode alone does not identify St Kilda. Browse other postcodes in South Australia, or widen the search to every Australian postcode.