south-johnstone postcode qldga Home ›› Postcode Finder ›› QLDGA ›› South-Johnstone South Johnstone local listingsThe suburb of South Johnstone is located in QLD and has a postcode of 4859. Free south johnstone business listing! Get the first free listing in south johnstone! Search and find other Postcodes in Queensland or widen the search to Postcodes in Australia.