This coin was issued in Australia.

The Mint says about this coin:

Buy the HRH Prince George Stamp and Coin Cover at The Perth Mint, featuring: Stunning sculpted reverse design of The Duke and Duchess of Cambridge with their new baby Design includes the name and birth date of the Royal baby $1 Aluminium Bronze Coin Australian Legal Tender Official Australia Post Stamp Beautifully Designed Presentation Envelope with certificate of authenticity