Top Men’s Performances of 2025: Leon Marchand Shines Again With 200 IM World Record
With the final days of 2025 approaching, it’s time to look back on the year of swimming and determine the top performances in the pool. The list will emphasize long course and championship-winning performances, and each swimmer is only eligible to appear on the list one time. And it should be no surprise that the top spot on this list belongs to a familiar face who fired off yet another record-shattering performance this year as he remained the world’s best swimmer.
1. Leon Marchand (France), 200 IM at World Championships (1:52.69 WR in Semifinal)
Photo Courtesy: Peter H. Bick
Following his masterful, four-gold-medal performance at the Paris Olympics, Marchand opted for a smaller program of events for his follow-up at the Singapore World Championships. He would only race the 200 and 400 individual medley, with sights on his third consecutive world titles in both events. The 200 IM world record was a clear target after Marchand missed the standard by only six hundredths in the Olympic final.
Ryan Lochte had held the world record since 2011 with a time of 1:54.00, but halfway through the semifinal round at Worlds, it became clear that mark was toast as Marchand opted to chase history in his first evening swim of the meet. He was out in 24.10, already eight tenths under world-record pace, and his incredible 32.13 on breaststroke put him almost two seconds under heading into the freestyle. Lochte out-split him slightly coming home, but Marchand still finished in 1:52.69 to obliterate the world record.
That would be his only global mark of 2025 but far from his only impressive swim. Marchand went on to win the world title the following day in 1:53.68, still well ahead of the previous record, and he added a world title in the 400 IM later in the week, remaining head-and-shoulders clear of the rest of the world. While he did not achieve anything noteworthy in the 200 breaststroke this year, he fired off some notable performances in the 200 butterfly and 400 freestyle at the U.S. Open in December. His 1:52.57 in the 200 fly made him the second-quickest swimmer in the world this year while a huge best time of 3:44.70 in the 400 free moved him into the world top-10.
2. Lukas Martens (Germany), 400 Freestyle at Swim Open Stockholm (3:39.96 WR)
Photo Courtesy: Emily Cameron
The long-pursued world record in the men’s 400 freestyle finally went down in 2025 thanks to the efforts of Martens, a 23-year-old German who was already the Olympic gold medalist in the event and now the only swimmer in history to break 3:40. Martens had been has fast as 3:40.33 in the event in early 2024 before winning a showdown with Elijah Winnington and Kim Woo-min in the Paris final. He returned in April this year to finish the job and become the fastest man ever.
Martens was in pursuit of a record held by fellow German Paul Biedermann from the polyurethane suit era. Biedermann had actually negative-split the previous world record, coming home in 25.77 on the final length to clip an Ian Thorpe record by a hundredth. That meant any swimmer gunning for his time had to be well under world-record pace entering the final stages of the race. On this day, Martens was; he hit the 300-meter turn more than three seconds under world record pace before coming back in 55.95, enough to finish in 3:39.96.
Three months later, Martens would back up his world record with a world title in the 400 free, out-dueling resurgent Aussie Sam Short for gold. He added a bronze medal in the 800 free in Singapore.
3. David Popovici (Romania), 100 Freestyle at World Championships (46.51)
Photo Courtesy: Emily Cameron
Three years after he knocked off a 13-year-old world record in the 100 free, Popovici is back on top in the blue-ribband event. In fact, he departed Singapore a double gold-medalist in the 100 and 200 free after turning to his signature finishing speed to stave off challenges from American rivals. In the 200 free final, Popovici closed in 26.43 to surpass Luke Hobson and win gold in 1:43.53. He needed another huge effort to get by Jack Alexy two days later in the 100.
Entering 2025, Popovici was no longer the standard-bearer in the 100 free. That title belonged to China’s Pan Zhanle after his stunning 46.40 effort in the Olympic final to clobber the world record. However, Pan was off his best form in 2025, failing to advance to the Worlds final of the 100 free. Still, Popovici had to deal with Alexy after the American went 46.81 in the semifinals to become the No. 3 performer in history.
In the final, Popovici was fourth to the 50-meter mark in 22.49, with neutral athlete Egor Kornev, Brazil’s Gui Caribe and Alexy all showing more speed. Once again, the Romanian’s otherworldly closing abilities shined through. Home in 24.02, he surged through the field and came to the wall in 46.51. The time was the second-fastest in history, within 0.11 of Pan’s world record. Notably, Popovici swam a full second faster than he did on the way to Olympic bronze one year earlier.
4. Hubert Kos (Hungary), 200 Backstroke at World Championships (1:53.12)
Photo Courtesy: Emily Cameron
Kos made a strong case for the list with a pair of world-record-setting efforts during the World Cup circuit, where he went nine-for-nine with backstroke wins. Kos sparkled at the final stop in Toronto, taking down a decade-old world record in the 200 back by a half second before adding a record in the 100 as well. But those performances in the 25-meter course could not overshadow his world-title-winning effort in the long course version of the 200 back.
Kos was already the Olympic gold medalist in the event, and he won the world title in 2023, but he faced a major challenge in Singapore from ascendant South African Pieter Coetze, who jumped out ahead of the field during the opening 100 meters. Kos bounced back to take the lead into the last turn, but Coetze had one last surge remaining. In the end, Kos got to the wall in 1:53.12, beating his best time by more than a second and becoming the fifth-fastest performer in history. Kos took down the European record previously held by Tokyo Olympic champion Evgeny Rylov.
The 22-year-old Hungarian is sure to face further challenges from Coetze and perhaps others in the future, but he is the world’s clear No. 1 in his signature event. Kos also had impressive performances in other events at the World Championships, securing bronze in the 200 IM while ending up fourth in the 100 back.
5. Caspar Corbeau, 200 Breaststroke at Toronto World Cup (1:59.52)
Photo Courtesy: Giorgio Scala / Deepbluemedia / Insidefoto
There will be one short course performance ranked among the top-five thanks to Corbeau’s incredible effort in the 200 breast during the final stop of the World Cup. Corbeau, 24, was never an international medalist on the senior level prior to 2024, when he won silver at the Doha World Championships in the 200 breast and then Olympic bronze in the event. Following another global bronze in 2025, he performed extremely well on the World Cup circuit, with seven breaststroke wins in nine tries.
Most impressive was his 200 breast in Toronto where Corbeau became the first swimmer ever to break 2:00. The performance came completely out of nowhere after Corbeau had clocked 2:01.63 and 2:01.68 during the first two stops. Both were victorious performances, the latter enough to take down Olympic champion Leon Marchand, but Corbeau went to another level in Toronto with his time of 1:59.52, erasing the 2:00.16 set by Russia’s Kirill Prigoda in 2018. Corbeau would also add a World Cup record in the 100 breast, and he ended the year as the gold medalist at the European Short Course Championships in the 100 breast.
Honorable Mention
The hardest swimmer to leave out of the top-five was Tunisia’s Ahmed Jaouadi, who put together two magical efforts in the distance races for gold medals. Jaouadi’s 800 time of 7:36.88 made him the third-fastest swimmer ever and the fastest ever in a textile suit. That swim was almost enough to put Jaouadi on this list. Later, he jumped to No. 6 all-time in the 1500 with his winning time of 14:34.41.
The only world-record breaker from 2025 to miss the top-five was Canada’s Josh Liendo, who produced a time of 47.68 in the 100 butterfly (short course) at the Toronto stop of the World Cup. As with Corbeau’s record later in the meet, Liendo came from well off the pace to set the new standard after Switzerland’s Noè Ponti and his Canadian teammate Ilya Kharun had dominated the event during the first two stops.
Coetze deserves mention for his breakout campaign in the backstroke events, which resulted in a gold medal and two silvers in Singapore. His winning effort in the 100 (51.85) moved him into a tie with Ryan Murphy for No. 3 all-time, and he sits seventh in the 200 back. In the sprint butterfly events, Maxime Grousset was dominant at Worlds, the highlight performance coming in the 100 when his time of 49.62 made him the second-fastest man ever behind Caeleb Dressel.
The Russian men capped off their strong return to international racing with a gold medal in the 400 medley relay at Worlds. The team of Miron Lifintsev, Prigoda, Andrei Minakov and Egor Kornev finished the race in 3:26.93, only 0.15 off the world record. Finally, this swim did not earn a gold medal, but credit Shaine Casas for giving Marchand a real push in the 200 IM final at Worlds. Casas earned silver in 1:54.30, making him the fourth-fastest performer ever behind Marchand, Lochte and Michael Phelps.
