Home Postcodes by state QLD 4819 Postcode 4819 4819 is the postcode for 7 localities in QLD: Arcadia, Florence Bay, Horseshoe Bay, Magnetic Island, Nelly Bay, Picnic Bay and 1 more. Localities with postcode 4819ArcadiaQLDFlorence BayQLDHorseshoe BayQLDMagnetic IslandQLDNelly BayQLDPicnic BayQLDWest PointQLD Postcode 4819 State or territory Queensland (QLD) Localities 7 Council area Townsville Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 4818 · Postcode 4820