Aussie pool queen Bronte Campbell has announced her retirement from competitive swimming so she can devote herself to revolutionising the activewear industry.

The winner of three Olympic golds and two world championship titles had been seriously looking at competing in the 2028 Los Angeles Games before she pulled the pin on a career that saw her achieve great success alongside her sister Cate.

Bronte, 32, and her coach had been drawing up how her lead-in to the next Olympics would look when she made the life-changing decision.

'I really believe the best things in my life are still coming. I believe it in my soul,' Campbell told Nine.

'If I speak to my seven-year-old self, who dreamed of going to one Olympic Games – it was all she ever wanted – and if I told that seven-year-old about all the things she was going to get to go do, all the people she was going to meet, and that the best things to come out of it wouldn’t be medals, but these incredible relationships, memories and experiences that are so far beyond the imagination of a seven-year-old ... she would think it was some sort of made-up, unrealistic future.'

Campbell named her second-place finish behind sister Cate in the 50m freestyle at the 2012 Australian Olympic trials as the favourite moment of her career.

'It was that first realisation of a dream coming true,' she said.

'It's not my biggest achievement by any stretch, but it was 100 per cent my favourite race and my favourite feeling I've ever had after a race.

'It was just absolute joy. That's a really special moment that will stay with me.

'It has honestly sustained me for my career. I’ve always loved that feeling and wanted to get close to it again.'

Campbell will now concentrate her efforts on the Earthletica activewear brand she co-founded – and she has sky-high ambitions for it.

'Our mission is to completely change the activewear industry – to eradicate virgin [non-recycled] plastics from activewear without compromising performance,' she revealed.

'The overall mission is that I want people to feel excited and optimistic about the future we're creating.'

Born in the African country of Malawi, Campbell came to Australia with her family in 2001 and won three golds and a bronze at the 2015 World Championships.

She won gold in the 100m freestyle relay at the 2016, 2020 and 2024 Olympics.

Campbell decided to have two years away from the sport following the Paris Games before deciding to leave the pool to live her green fashion dream.

'When I was seven, people laughed at my dreams of the Olympics and said not many people do that,' she recalled.

'Now I'm in a fresh new world and people think it's very unrealistic to change the complete landscape of activewear. 

'I’m like, yeah, but there was a 0.0017 per cent chance of [me] ever going to one Olympics. 

'And there's something exciting to me about chasing really big goals.'

Campbell married Benfield Lainchbury in a stunning ceremony near Sydney's Palm Beach earlier this year.

He played a pivotal part in the swimmer's decision to return to the pool after an 18-month break following the 2021 Tokyo Olympics.

The couple had two celebrations with the first being an intimate ceremony at Palm Beach's Lilypad, a boat villa that floats on Pittwater Bay.

Only family and the bridal party attended, but the white party occurred a week later at North Bondi Surf Lifesaving Club, where she changed into a swimsuit and glitter mesh dress as she hit the water with her guests.