Four-time Olympic gold medallist Ariarne Titmus has announced her shock retirement from swimming.
The 25-year-old, who grew up in Tasmania, will retire as one of the greatest distance swimmers of all time.
She said she expected to return to swimming following a break after the Olympics, but changed her mind.
'It's a tough one but one that I'm really happy with,' she said in an Instagram post.
I've always loved swimming, it's been my passion since I was a, a little girl, but I guess I've taken this time away from the sport and realised some things in my life that have always been important to me are just a little bit more important to me now than swimming and that's OK, but yeah, here we are.'
At the Paris Olympics last year, Titmus achieved an historic third individual Olympic gold medal, winning the 400m freestyle in the race dubbed 'the race of the century', where she defeated the other two previous world record holders of this event - American all-time great Katie Ledecky, and Canadian swimming prodigy Summer McIntosh.
In doing so, Titmus became the first Australian athlete since Dawn Fraser in 1964 to win back-to-back gold medals in the same event.
Ariarne Titmus has called time on a career that has made her one of the greatest swimmers in the history of the sport
The 25-year-old won four Olympic gold medals, including this one for the 400m freestyle at the Paris Games last year
Titmus overcame a health battle before the Olympics when she had surgery to remove an ovarian tumour
Before the Paris Games, Titmus underwent surgery to remove an ovarian tumour.
Titmus steps away from the sport as the current 200m world record holder, having won a staggering haul of 33 international medals including eight Olympic medals – four gold, three silver and one bronze – and four world titles.
She defended her 400m freestyle title in Paris, making her the first Australian since Dawn Fraser at the 1964 Tokyo Games to win two straight golds in the same event.
More to come...