Home Postcode finder SA Auburn Auburn postcode SA Auburn is a locality in South Australia covered by postcode 5451. Postcode 5451 State or territory South Australia (SA) Region Sa Subs Near 1 Add a free Auburn business listing More business listings in Auburn Businesses in AuburnAuburn Primary SchoolSt Vincent St · 08 88492112 Common questionsWhat is the postcode for Auburn?Auburn, SA has the postcode 5451.What state is Auburn in?Auburn is in South Australia (SA).Does postcode 5451 cover more than one suburb?Yes. Postcode 5451 covers 2 localities, so the postcode alone does not identify Auburn. Browse other postcodes in South Australia, or widen the search to every Australian postcode.