Home Postcodes by state VIC 3921 Postcode 3921 3921 is the postcode for French Island, VIC. Localities with postcode 3921French IslandVIC Postcode 3921 State or territory Victoria (VIC) Localities 1 Council area Unincorporated Vic Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 3920 · Postcode 3922