newcastle postcode nsw Home ›› Postcode Finder ›› NSW ›› Newcastle Newcastle local listingsThe suburb of Newcastle is located in NSW and has a postcode of 2300. Free newcastle business listing! 1Newcastle Grammar School60 Newcomen St 02 492958112Newcastle Grammar SchoolCnr Parkway & Union Sts 02 492521213Newcastle East Public SchoolCnr Brown & Tyrell Sts 02 49292911 View more business listings in newcastle Search and find other Postcodes in New South Wales or widen the search to Postcodes in Australia.