But it was the Commonwealth Games that gave her the belief she belonged there.

Now she'll help the next batch of Olympic stars feel the same way in new her role as the 2022 Birmingham Commonwealth Games chef de mission.

Thomas is the first female to hold the role, having been Steve Moneghetti's understudy at the Gold Coast Games last year.

The 43-year-old shone in the pool at three Commonwealth Games, winning a total haul of nine gold, two silver and one bronze after making her debut at the '94 Victoria Games in Canada.

She won two of her gold there and credited that for preparing her to go on to bigger and better things.

Her crowning Commonwealth glory was at Manchester in 2002, when she claimed five gold, a silver and a bronze.

"It was a great experience [in Victoria] ... I think it was my second year on the Australian swim team," Thomas said on Tuesday.

"I just went in with not a lot of expectations. I was a pretty shy country girl and still learning the trade and I was able to win the 100-metre butterfly at that event.

"It was a life changing moment for me ... and it gave me the belief that I was good enough to be competing on the world stage.

"That's what a Commonwealth Games can do for an athlete."

Thomas will get straight to work as chef de mission, travelling to Birmingham in three weeks to do some reconnaissance of the Games venues for 19 sports.

She wants to get a feel for the logistics of the event - how far the venues are from the village and those kinds of things.

Australia are planning to send more than 400 athletes to it as they look to cling to the top of the medal table, which they reclaimed on the Gold Coast.

Thomas said working with Moneghetti, who was the chef de mission at the past three Commonwealth Games, had prepared her for the role - especially his style of leading.

While Birmingham is a far cry from the glitz and glamour of the Gold Coast, she was happy to lead her first Games on foreign soil.

"I'm actually glad in a way because at a home Games there's more eyes on you, greater scrutiny and more press," Thomas said.

"In retrospect I think it's great that Monas had the Gold Coast. It's great being able to learn from him the last few games and see the way he conducts himself and the way he leads the team.

"In many respects I really relate to that. It was never about Monas, it was always about the team."