The women's 400 metre freestyle event at the 2024 Summer Olympics was held on 27 July at Paris La Défense Arena.

[1] Australia's defending Olympic champion Ariarne Titmus, Canada's Summer McIntosh and the USA's Katie Ledecky were the favourites going into the event.

Ariarne Titmus of Australia was the defending champion in the event, while the USA's Katie Ledecky was runner up at the previous Olympics.

Ledecky also held the Olympic record of 3:56.46 from Rio 2016 and won the event at the 2022 World Championships.

[5][6] Finally, the rest of the spaces were filled by athletes who had met the Olympic Consideration Time (OCT), which was 4:09.14 for this event.