Home Postcode finder SA Lewiston Lewiston postcode SA Lewiston is a locality in South Australia covered by postcode 5501. Postcode 5501 State or territory South Australia (SA) Region Sa Subs Near 1 Add a free Lewiston business listing More business listings in Lewiston Businesses in LewistonJim's Fencing Adelaide PlainsLewiston SA, Australia · 131546 Common questionsWhat is the postcode for Lewiston?Lewiston, SA has the postcode 5501.What state is Lewiston in?Lewiston is in South Australia (SA).Does postcode 5501 cover more than one suburb?Yes. Postcode 5501 covers 14 localities, so the postcode alone does not identify Lewiston. Browse other postcodes in South Australia, or widen the search to every Australian postcode.