The popular 25-year-old has not featured since winning her home grand slam at the Australian Open in January, becoming the first female Aussie singles champion of the tournament since Chris O'Neil in 1978.
Announcing the news on her Instagram page, Barty cited achieving a lifelong goal of winning Wimbledon last year as a primary factor behind her decision as well as being "spent physically".
But Barty is by no means the first sporting hero to retire at the top of their game. Below we take a look at some other examples of those who have exited as champions.
The 1993 Formula One season was largely dominated by one man – Williams driver Alain Prost. The Frenchman had to battle hard with the iconic Ayrton Senna at the start of the campaign, with them each taking three wins from the first six races of the season. However, a run of four straight victories for Prost were followed by a string of retirements for Senna, ensuring a fourth world title that provided the ideal ending to a glittering career.
One of the most successful managers in world football, Alex Ferguson began a 27-year stint at Manchester United after an excellent spell at Aberdeen. The Scot won 28 major trophies at Old Trafford, including 13 Premier League titles, five FA Cups and two Champions Leagues. His final trophy came with top-flight glory in 2012-13, and 17 days later he brought the curtain down.
Considered one of the greatest quarterbacks of all time, Peyton Manning won his first Super Bowl with the Indianapolis Colts in 2007 and, after an injury-blighted season that raised doubts about his ability aged 39, he added a second with the Denver Broncos in 2016, bowing out on the ultimate high.
RICHIE MCCAW, DAN CARTER
New Zealand became the first nation to successfully defend the Rugby World Cup trophy by beating Australia 34-17 in the final at Twickenham in 2015, adding to their success on home soil four years prior. It proved the end of the line for captain Richie McCaw, who was at the time the most capped player in rugby union with 148 appearances for the All Blacks, as well as mercurial fly-half Dan Carter. Ma'a Nonu, Conrad Smith and Kevin Mealamu were also among an influential contingent that opted to end their international careers.
In defeating Andre Agassi in the final of the 2002 US Open, the same opponent he overcame to win his first grand slam 12 years prior, Pete Sampras secured his place among the greats in men's tennis. It was a then-record 14th major singles title for a male player for the American, a milestone that has since been surpassed by Roger Federer, Rafael Nadal and Novak Djokovic, but he did not compete again and announced his retirement almost one year later.
PHILIPP LAHM, MIROSLAV KLOSE
At 31 you still have a number of years ahead of you in football. However, after lifting the World Cup trophy with Germany in 2014, Philipp Lahm decided to call time on his international career and focus on club football with Bayern Munich. The versatile full-back made 113 appearances for his country and was joined by fellow centurions Per Mertesacker and Miroslav Klose – whose tally of 71 international strikes is a German record – in switching focus to domestic matters.
A first grand slam at Wimbledon in 2013 appeared to be the breakthrough moment for a 28-year-old Marion Bartoli, but reality proved very different. The Frenchwoman defeated Sabine Lisicki – who had overcome pre-tournament favourites Serena Williams and Agnieszka Radwanska – in the All England Club final, but announced her retirement during the Western and Southern Open just 40 days later due to persistent injuries. She attempted a comeback in 2018 but continued setbacks and injuries curtailed those plans.
Nico Rosberg had engaged in several intense battles with Lewis Hamilton before finally getting the better of his Mercedes team-mate to become Formula One world champion in the 2016 season. Still only 31, Rosberg had potentially several more years in F1 but the German instead opted to depart having reached the pinnacle of his sport.