Home Postcode finder SA Avon Avon postcode SA Avon 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 Avon business listing Be the first listing in Avon Common questionsWhat is the postcode for Avon?Avon, SA has the postcode 5501.What state is Avon in?Avon 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 Avon. Browse other postcodes in South Australia, or widen the search to every Australian postcode.