For the first time in more than a decade, Katie Ledecky may not be the most feared swimmer in the pool. That honor now belongs to Summer McIntosh, the Canadian teenager looking to do what only Michael Phelps has done before her: win five individual gold medals at a single world swimming championships.
Their clash in the 800m freestyle on 2 August is set to be the defining moment of the weeklong meet in Singapore. Ledecky, the most decorated female swimmer in history, is bidding for an unprecedented seventh world title at the distance she has dominated since 2013. McIntosh, just 18, is the only swimmer to have beaten her at 800m in the past 15 years.
They now share more than a lane line. McIntosh grew up with a Ledecky quote on her bedroom wall. Now she stands ready to challenge her idol, and perhaps even eclipse her. “Katie always brings the best out of me,” McIntosh said. “Which is why I’m never nervous to race her.”
McIntosh arrives in Singapore in historic form, having broken world records in the 400m individual medley, 200m IM and 400m freestyle over a dizzying five-day span at Canada’s national trials in June. Her 3:54.18 in the 400m free obliterated Ariarne Titmus’s previous world standard and set the marker for a meet that could be her coronation. While she holds the world’s fastest time this year in four events, she is not the official top seed in either the 400m or 800m freestyle, both of which are led by Ledecky. Her 8:05.07 in the 800m is the third-fastest in history, behind only two swims by the American.
Quick Guide
World Swimming Championships 2025
Show
The schedule
The swimming portion of the World Aquatics Championships takes place from 27 July through 3 August at the Singapore Sports Hub.
The heats start at 10am local time (2am GMT). The semi-finals and finals start at 7pm local time (11am GMT). The full schedule is available in PDF format or on the World Aquatics website.
How to watch
In the United States, coverage will be available on NBC and streaming service Peacock.
In the United Kingdom, Aquatics GB holds the UK rights to stream events.
In Australia, the Nine Network will provide broadcast coverage throughout the championships.
In Canada, events will be broadcast live on CBC, with streaming options via CBC digital platforms.
For other countries and full international broadcast listings, visit the World Aquatics broadcast page.
Additionally, the World Aquatics Recast channel will re-air all sessions of the meet, heats and finals for a fee.
That they will meet on the penultimate day of competition lends the showdown even more drama. By then, McIntosh may already have claimed three or four golds. But the 800m is Ledecky’s fortress. It is, in US team director Greg Meehan’s words, the “gold standard”.
McIntosh has said she chose to add the 800m this year because it presents the biggest challenge. She will need every ounce of stamina, especially with a projected 14 or 15 races in eight days, thanks to relay duties and quick turnarounds like Sunday’s 400m freestyle final followed 30 minutes later by the 200m IM semi. “It’s a very challenging schedule she’s set for herself,” Canada head coach Iain McDonald said. “But she thrives on challenge.”
Notably absent from the 800m start list is Ariarne Titmus, the Paris Olympic gold medallist in the 400m freestyle, who is taking the year off. In that race, McIntosh took silver and Ledecky claimed bronze. Ledecky, however, won gold in the 800m in Paris, continuing her historic dominance in the event. This race offers a reordering of the long-distance hierarchy and potentially a watershed moment in the sport’s history. A McIntosh victory would not only dent Ledecky’s momentum heading into her home Olympics in LA 2028 but signal a true generational shift.
Yet Ledecky remains a daunting force. In May, she rewrote her own nine-year-old 800m world record, clocking 8:04.12 in Florida. And while McIntosh’s programme is more grueling, Ledecky’s focused schedule may allow her to conserve energy for the marquee clash.
Even if McIntosh comes up short in the 800m, she remains the overwhelming favorite in the medley events and the 200m butterfly. Her versatility is such that McDonald says it’s hard to even name her best event. Should she complete the sweep, she would join Phelps as the only swimmer to win five individual golds at a single worlds.
But McIntosh isn’t the only prodigy drawing attention in Singapore. China’s Yu Zidi, all of 12 years old, will line up in the 200m and 400m IM and the 200m fly. Her qualifying times would have placed her fourth in each of those events at the Paris Olympics. Yu is already 15 seconds faster than McIntosh was at the same age. “There’s always someone coming up next,” McDonald said. “That’s the nature of this sport.”
In the men’s events, all eyes will be on France’s Léon Marchand, the four-time Olympic gold medallist who rocked La Défense Arena not even a year ago in delivering a “perfect” home Games. His coach, Bob Bowman, has urged a more streamlined approach for Singapore: Marchand has dropped the 200m fly and 200m breaststroke to focus on the 200m and 400m IM, with the possibility of relay appearances.
Marchand is expected to defend his world titles and may even challenge Ryan Lochte’s long-standing world record of 1:54.00 in the 200m IM. “The expectation is for him to do as well as he can where he is now, not where he was last summer,” Bowman said. Marchand returned to Bowman’s programme in Austin after a brief post-Olympic slump. Whether he can conjure the same brilliance in Singapore, three years out from LA 2028, will be one of the meet’s central questions.
Sprinters dominate the rest of the men’s programme. China’s Pan Zhanle, fresh off a blistering 46.40 to win Olympic gold in Paris, will defend his 100m free title. Romanian David Popovici, who held the world record before Pan’s rise, will be a top contender in both the 100m and 200m free. Ireland’s Daniel Wiffen, the reigning world champion in the 800m and 1,500m freestyle, is also aiming high. The 22-year-old has his sights set on Zhang Lin’s super-suit-era world record of 7:32.12 in the 800m, a mark many thought untouchable. “I believe that all world records will be broken,” Wiffen said recently. “And I’m willing to push myself to that limit to get it.”
Great Britain’s Duncan Scott, an eight-time Olympic medallist, has streamlined his own programme in pursuit of that elusive individual world title. “That event is all I’ve got now, so I’m going to put all my eggs in one basket,” he said of the 200m IM, where he’ll again face Marchand.
Scott also anchors Britain’s men’s 4x200m freestyle relay, the defending Olympic champions. The quartet – Scott, Matt Richards, Tom Dean and James Guy – now seek their first world title together.
Elsewhere, American star Gretchen Walsh is looking to convert her short-course success into long-course dominance, and Australia’s Mollie O’Callaghan returns as a serious threat in the sprint freestyles.
The Singapore Sports Hub’s new 4,800-seat arena is a fitting stage for the post-Olympic reset. Nearly 30 nations are expected to win medals, a testament to swimming’s growing global depth. But for all the newcomers and national aspirations, the defining narrative may still come down to two swimmers in a single race. “Perhaps Summer would be the one who wanted to challenge that,” McIntosh’s coach Fred Vergnoux said of her decision to take on Ledecky at 800m. “She accepted the challenge a bit early, for these worlds. But I think she’s ready.”
