The Whitsundays and Whitsunday Islands are situated on the east coast of Australia, about half way up the Queensland coast in the middle of the Great Barrier Reef. The Whitsunday Islands group is part of a larger group of island known as the Cumberland Islands comprising over 164 islands.

Over the years various groups of these islands have received official names and most of those which lie off the coast between Mackay and Bowen were named 'The Cumberland Isles' by Lieutenant James Cook, RN in June 1770. However this name, while still officially in place as 'The Cumberland Islands', has faded somewhat from public perception to be replaced by the unofficial but now almost universal name 'The Whitsunday Islands'. This arises because Cook in 1770 gave the name 'Whitsunday's Passage' to the main waterway among the islands though in later years the possessive 's' was dropped.

While there is an official designation of which islands lie within the Cumberland group (broadly those between Snare Peak Island in the south and Hayman Island in the north) there is no such designation of which islands comprise the 'Whitsunday Islands' and definitions vary as frequently as the question is asked, depending on the eye and the interest of the beholder.