Home Postcode finder SA Mount George Mount George postcode SA Mount George is a locality in South Australia covered by postcode 5155. Postcode 5155 State or territory South Australia (SA) Region Sa Subs Near 2 Add a free Mount George business listing Be the first listing in Mount George Common questionsWhat is the postcode for Mount George?Mount George, SA has the postcode 5155.What state is Mount George in?Mount George is in South Australia (SA).Does postcode 5155 cover more than one suburb?Yes. Postcode 5155 covers 2 localities, so the postcode alone does not identify Mount George. Browse other postcodes in South Australia, or widen the search to every Australian postcode.