Coffin Bay Peninsula is a peninsula located at the south west end of Eyre Peninsula in South Australia. It extends in a north westerly direction from its connection to Eyre Peninsula and is bounded by Coffin Bay, Port Douglas and Yangie Bay to the north, the Great Australian Bight to the west and Avoid Bay to the south. Its extremities are Point St Isaac in the north, Point Whidbey in the south west, Point Longnose in the north east and Point Avoid in the south east.