Belcher, who won gold in the 470 class with Will Ryan in Tokyo, will lead about 70 Australian athletes into Sunday night's closing ceremony.

"Incredibly proud," Belcher told reporters on Saturday.

"it's a real privilege to not only be an Olympian but to represent Australia and to deliver a great performance alongside Will.

"To carry the flag it's something that is really humbling and I'm super proud to be able to achieve that.

"I will be carrying the flag not just for those who are here but for all those now in quarantine back home or headed elsewhere. This will be for all of us."

Belcher's Tokyo gold medal follows a gold at the 2012 London Games and a silver medal the 2016 Rio Olympics.

Australian team chef de mission Ian Chesterman said Belcher was a most deserving recipient of the flag-bearer honour.

"Mat is steeped in the Olympic tradition and very successful in what he has achieved.

"Two golds and a silver over those three Games is quite something. It's an extraordinary record of achievement, performing at this level of competition."

Belcher's Tokyo triumph with Ryan came after the pair, like most Australian Olympians, entered Tokyo with no international competition for 18 months because of the coronavirus pandemic.

"Everyone's preparations coming into these Games were quite different and very different to what you probably would have hoped for," Belcher said.

"A lot of teams were much more creative in the way that they were training domestically (with the) lack of competition internationally.

"So to even get to the Games, I sensed a bit of relief, particularly in our group, of just finally being able to have that opportunity to compete.

"The focus was so much on performance, there was really no distractions, it was 100 per cent everything about delivering your best performance."

Belcher becomes the second 470 class sailor to carry Australia's flag at the closing ceremony, with his 2012 partner Malcolm Page given the honour at the London Games.

It's not Belcher's first time carrying a flag at an Olympic closing ceremony. As a teenager he carried the Olympic flag at Sydney 2000.

Australian Associated Press