Home Postcode finder QLD South Johnstone South Johnstone postcode QLD South Johnstone is a locality in Queensland covered by postcode 4859. Postcode 4859 State or territory Queensland (QLD) Region North QLD Add a free South Johnstone business listing More business listings in South Johnstone Businesses in South JohnstoneSouth Johnstone State SchoolEast Ave · 07 40642182St Rita's Primary School8 Green St · 07 40642153 Common questionsWhat is the postcode for South Johnstone?South Johnstone, QLD has the postcode 4859.What state is South Johnstone in?South Johnstone is in Queensland (QLD).Does postcode 4859 cover more than one suburb?Yes. Postcode 4859 covers 2 localities, so the postcode alone does not identify South Johnstone. Browse other postcodes in Queensland, or widen the search to every Australian postcode.