The 1966 1c coin was the second highest mintage 1966 coin and was minted at the Melbourne branch of the Royal Mint (238,990,00 coins), the Perth branch of the Royal Mint (26,620,000 coins) and the RAM in Canberra (146,140,000 coins) . Distinguishing the mint that manufactured this coin is done by looking at the left-most whiskers of the possum. If the left most whisker is blunted then the coin was minted in Melbourne, if the second from the left most whisker is blunted then the coin was minted in Perth. If neither are blunted then the coin was minted in Canberra. The images above show the Canberra minted coin at the top and a Melbourne minted coin below. The image at the bottom of this article shows a Perth minted 1c coin.
You can find out about the other 1966 decimal coin mint marks by looking at our 1966 Australian decimal coin mint mark article.