The resort, near Arrowtown, received the accolade at the 2016 World Golf Awards announced at the weekend in Portugal.
The awards celebrate and reward excellence in golf tourism, world-class courses and golf destinations, based on votes from the public and industry professionals. A vote from an industry professional carries five times the weighting of a public vote.
Other nominees in the category were InterContinental Fiji Golf Resort and Spa and Joondalup Resort, in Australia.
Millbrook also won the best golf hotel in New Zealand award, beating Formosa Golf Resort (Auckland), Kauri Cliffs, Lakes Resort Pauanui, Terrace Downs Resort and The Farm Cape Kidnappers.
Millbrook director of operations Brian Howie said the resort was honoured to receive the award, which acknowledged both its 27-hole championship course and its passion for hospitality and delivering first-class customer service.
''In 1993, the Ishii family set out to create a resort of international standing to be built in harmony with the land.
''This award is an endorsement of their vision and business strategy [and] recognises Millbrook is a resort of international standing ...'' Mr Howie said.
Millbrook has also recently won New Zealand's best resort spa at the World Spa Awards 2016 and was recognised as New Zealand's best luxury hotel at the 2016 World Luxury Hotel Awards.
''These award wins demonstrate our success in achieving our vision for Millbrook to be not only the first choice of lifestyle resort, but a destination in itself,'' Mr Howie said.
The original 18-hole course was designed in 1993 by Sir Bob Charles and in 2009 Greg Turner designed an additional nine holes and remodelled the existing 18 holes to provide three interchangeable 18-hole course configurations.
In 2014 Millbrook acquired 66ha of land beside the resort, which would enable further development of an additional nine holes that will provide even further options for guests and golfers.
The most recent accolade comes ahead of the ISPS Handa New Zealand Golf Open to be hosted by Millbrook in March.
The Open is part of the PGA Tour of Australasia, held in partnership with Japan Golf Tour which will have leading professional golfers from the Japan tour playing in the four-day event.
Meanwhile, New Zealand was named Oceania's best golf destination in 2016, beating Australia and Fiji, with Clearwater Golf Course, in Christchurch, named Oceania's best golf course.
Other nominees in that category were Natadola Bay in Fiji and the Royal Melbourne Golf Club West Course, in Australia.
Clearwater also won New Zealand's best golf course. A total of 12 courses were nominated in that category, including Millbrook, The Hills, Jacks Point and Southland Golf Club.
