He had been fighting pancreatic cancer since late last year.
Sir Eion made a big difference in New Zealand as a philanthropist in sport, education, youth, arts, sports and health.
VIDEO: Sir Eion was made a distinguished fellow by the Institute of Directors at a special ceremony in April
He was the chairman of numerous charitable trusts and organisations, including the Edgar Olympic Foundation, New Zealand Dementia Prevention Trust, and Winter Games NZ Charitable Trust.
He was also an official patron of Diabetes New Zealand, the New Zealand Sports Hall of Fame and the New Zealand Football Foundation.
Sir Eion helped in the creation of the University of Otago's Edgar Diabetes and Obesity Research Centre, and in the creation of the southern hemisphere's largest single-building indoor sports arena, Dunedin's Edgar Centre.
He was the chancellor of the University of Otago between 1999 and 2003 and awarded Honorary Doctorate of Laws for outstanding service.
Sir Eion spent 20 years as the chairman of Forsyth Barr Group in Dunedin, until his retirement in 2018.
His friend of 36 years, Queenstown Lakes Mayor Jim Boult, confirmed that Sir Eion had died about noon today.
In an emotional tribute, he called Sir Eion "a good Kiwi man".
"He's been an absolute gift to our district, and the whole of New Zealand," he said.
"I'm devastated.
"He's just been one of those people, whenever there's a been a cause Eion's been there to support it."
He was generous not only with his own money, but also in convincing others to support causes as well, Mr Boult said.
"He will be enormously missed."
