Home Postcode finder SA Willaston Willaston postcode SA Willaston is a locality in South Australia covered by postcode 5118. Postcode 5118 State or territory South Australia (SA) Region Sa Subs Near 1 Add a free Willaston business listing More business listings in Willaston Businesses in WillastonGawler Automatic Transmissions6 Little Paxton St · 0885222558 Common questionsWhat is the postcode for Willaston?Willaston, SA has the postcode 5118.What state is Willaston in?Willaston is in South Australia (SA).Does postcode 5118 cover more than one suburb?Yes. Postcode 5118 covers 16 localities, so the postcode alone does not identify Willaston. Browse other postcodes in South Australia, or widen the search to every Australian postcode.