The British breaststroke maestro may not boast multiple-medal hauls as do Phelps or Bolt, but he's as dominant as the Jamaican and American were at the height of their peak.
His supreme rule in the pool in the 100m breaststroke is two years short of a decade and includes three world titles in his pet event. Still only in his mid-20s, Peaty is reshaping the breaststroke discipline, not playing by the rules that used to govern the event.
For a brief moment, Peaty held the 20 fastest times in history before Dutchman Arno Kamminga spoiled his one-man party with a blistering 57.92 seconds at the Netherlands trials in April. Kamminga is only the second man behind Peaty to have swum faster than 58 seconds.
Peaty had dipped below 58 seconds an incredible 18 times, which he did for the first time at the 2015 British Championships when he broke Cameron van der Burgh's world record.
Exclusive Olympic 100m breaststroke club
To Peaty's mind, barriers are made to be broken; he was the first man to go sub-58 seconds before raising the bar to moon-landing levels when he set a global mark of 56.88.
"You're basically going somewhere that no one on the planet has ever been before, so you need to have something a bit different and have something about you," Peaty told Olympics.com last year. "You need a different energy and a different focus.
"I want to set a legacy that will hopefully stand the test of time. I've never been more driven, and I don't intend to change now."
He has lowered the global mark four times since his first dive into world-record territory in 2015 and he would like nothing more than to do it again in Tokyo and to top it off with his second straight Olympic title.
A victory would see him join the legendary KITAJIMA Kosuke of Japan, the only swimmer to have won back-to-back Olympic titles in the 100m breaststroke – in Athens 2004 and Beijing 2008.
(2021 Getty Images)
No regrets
Kamminga is gaining ground on Peaty, but the Uttoxeter swimmer's spectacular personal best is almost a second faster than that of the Dutchman and he still has plans to improve on his world-record time.
"It sounds very cliched, but I'm very obsessed with continuous improvement and continually pushing the boundaries of what is possible," Peaty told The Guardian. "I don't want to end my career and go: 'I should have done that, or I should have done this.' And while getting a world record is obviously very, very hard, it's never impossible. I think it's within my reach if I get my preparation right during these next six days."
In 2014, a teenage Peaty burst into global swimming consciousness when he beat his idol, London 2012 champion Van der Burgh, at the 2014 Commonwealth Games in Glasgow.
Peaty's rise since then has been nothing short of meteoric, testing the limits of the event almost every time he got into the pool at a major championship. Two years later, he claimed his famous Olympic victory usurping Van der Burgh of his crown.
(2018 Getty Images)
Ironically, Van der Burgh challenged the air of invincibility that had since surrounded Peaty when he beat him into second place in the 50m breaststroke at the 2018 Commonwealth Games.
Peaty was left dejected after suffering his first defeat in four years, prompting him to do some introspection.
"After Rio, you get the post-Olympic blues, but my deepest low was at the end of 2018," Peaty told the Olympic Channel.
"I was the fastest man on the planet, so why was I losing? That doubt crept up. There wasn't really that much belief in myself.
"After the Commonwealths, towards the end of the year, I didn't have any races," he continued. "And when you involve off-season and you involve partying and drinking, that's a depressant in itself, so I was doing that a lot. I kind of, not went off the rails, but I didn't really have that overwhelming motivation to perform at something. And I am a performer, so if I don't have something to perform at, I completely lose my track."
Peaty has bounced back with aplomb, smashing the world record in the semi-final at the 2019 world championships to become the first man to break the 57-second barrier.
Armed with the world record and buoyed by his third consecutive global title, Peaty is on the cusp of another historic swim at the Olympic Games.
He posted the fastest time going into Monday's 100m breaststroke final at the Tokyo Aquatics Centre. Asked about his expectations for this second appearance at a final at the Olympic Games, Peaty answered with a cliffhanger.
"Every day has new challenges, new victories, so as long as the sun rises and I'm awake, and my eyes are open, anything can happen," he said following his semi-final race.
"But obviously, Olympic finals are Olympic finals, and I am looking forward to it."