AUSTRALIA's newest ultra-luxury private island resort, the One&Only Hayman Island, is open for business and started welcoming guests on Tuesday.

Already a Whitsunday icon, the resort has undergone an $80 million investment and "rebirth" as part of the exclusive One&Only collection.

The 294ha island was first developed by airline magnate Reg Ansett in the 1950s.

It underwent a $300 million redevelopment in the 1980s before being bought by Mulpha nine years ago.

Now owned by Mulpha Australia and managed by Kerzner International, the newly refurbished Hayman Island is One&Only's first resort in the Asia Pacific region.

Kerzner International CEO Alan Leibman said the organisation was excited to start welcoming guests and unveiling the stunningly refurbished resort.

"I think Hayman Island has a very special place in many Australians' hearts so for us at One&Only to have the opportunity [to come here] has been truly amazing," he said. One&Only Hayman Island's grand opening coincided with the return of Qantas to the Whitsundays on Wednesday.

Some of the first passengers travelling on Qantas' new Sydney - Hamilton Island service were also among the first guests to experience the opulence of the newly re-branded resort.

Hamilton Island CEO Glenn Bourke, who was a guest of One&Only Hayman Island last night, said he and Hamilton Island owner Bob Oatley welcomed the new premium product to the Whitsunday market place.

CEO of Whitsundays Marketing and Development Limited (WMDL), Danial Rochford, who also visited the resort, said the One&Only re-branding had taken Hayman Island to a level of luxury not seen before anywhere in Australia.

"The One&Only brand is significant not only for the region but for Australia - it's one of the most globally recognised luxury brands in the world," he said.

Mr Rochford said the luxury market was going "from strength to strength" post GFC.

One&Only Hayman Island is the first resort in the state to officially fly a Queensland flag, which was raised by Tourism Minister Jann Stuckey yesterday afternoon. The flag depicts a Union Jack and blue Maltese Cross with a crown.