The name Whitsunday was given by Captain James Cook, the first European to navigate the east coast of Australia in 1770. He was struck by the beauty of the area and named the island after "Whit Sunday", the seventh Sunday after Easter in the Christian calendar. Amusingly, it later turned out his calendar was wrong, it was Whit Monday, but the name has stuck!
Before British colonisation, Aboriginal people had traditionally used the trees in the area for timber. Evidence of this Indigenous history can be found at the Nara Inlet on Hook Island, where you can observe Aboriginal cave paintings (which can be accessed by boat, either on private charter or on one of the backpacker sailing yachts that sometimes stop in).
After the Aboriginal population had dwindled away through European diseases and bloodshed, white settlers also logged the area. Nowadays, there is no visible trace of logging on the landscape, just the old dam that was used by the sawmill in Cid Harbour on Whitsunday Island, and some curious bleating from the forest on some of the islands. Goats were introduced by the colonialists so that ship wreck survivors could find food, and later so that loggers could have something to hunt in the event that food ran out!