The podium protagonists include three women who have held or broken the World record since 2022: the standard held by Katie Ledecky (USA) since she claimed Rio 2016 Olympic gold, passed to Tokyo Olympic champion Ariarne Titmus(AUS) in 2022, before Summer McIntosh (CAN) broke the mark in spring 2023. 

Final: July 27, 8.52pm - Paris La Defense Arena (heats, morning of the same day)

Titmus then settled the argument with to retain the global crown in 3:55.38 last year in Fukuoka on the last occasion the best in the world gathered for a rested fight. 

For a number of reasons, defending champion Titmus will take to her blocks as favourite for the title but among the biggest factors in the fight is the scorching 1:52.23 World record she set over 200m at Australian trials as a swimmer who rook silver in the 800m as well as gold in the 200 and 400m in Tokyo. 

In Titmus, we find towering sprint and endurance strengths in the 200-800m range. Ledecky has, of course, demonstrated such skills, too, as 800m Olympic champion at the past three Games, starting with London 2012 at 15 years of age, and 200 and 400m champion in 2016, her fourth solo gold the inaugural 1500m title in Tokyo. 

In the longer distances, Ledecky remains favourite, her margin of advantage on the clock over the rest rock solid going into Paris, though for the first time in her international career, she was beaten in an 800m race: in February this year, McIntosh  clocked 8:11 ahead of the American at the Southern Zone South Sectional Championships in Florida, where they both train, in different programs. 

McIntosh is the third swimmer in the race 400m with 200m speed (1:53.65, WJR, 2023) and 800m endurance. At 1:52.23 and 3:55.38, however, there can be no question that Titmus, a proven racer with fiery response skills, has charted pioneering waters that the rest have yet to reach. 

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In the rest of this article: the stats, the facts, the Tokyo 2020ne flashback and an overview of Olympic 400m free history.