Home Postcode finder WA Mornington Mornington postcode WA Mornington is a locality in Western Australia covered by postcode 6221. Postcode 6221 State or territory Western Australia (WA) Region Wa Subs 3 Sth Rd Add a free Mornington business listing Be the first listing in Mornington Common questionsWhat is the postcode for Mornington?Mornington, WA has the postcode 6221.What state is Mornington in?Mornington is in Western Australia (WA).Does postcode 6221 cover more than one suburb?Yes. Postcode 6221 covers 2 localities, so the postcode alone does not identify Mornington. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.