Women's 400 metres world record progression

The first world record in the 400 m for women (athletics) was recognized by the International Amateur Athletics Federation, now known as the World Athletics, in 1957.

To June 21, 2009, the IAAF has ratified 27 world records in the event. Their 2009 record progression list, however, lists 26 records.^[1]

Indoor records are run over two laps of a shorter 200 metres track. "y" indicates marks were set over the 440 yards (402.34 m) imperial distance, and an asterisk indicates a record was repeated. All records since Kratochvílová's 49.59 in 1982 were ratified by the IAAF.^[2]

(y) indicates time for 440 yards (402.34 metres), ratified as a record for this event
(+) plus sign denotes en route time during longer race

The "Time" column indicates the ratified mark; the "Auto" column indicates a fully automatic time that was also recorded in the event when hand-timed marks were used for official records, or which was the basis for the official mark, rounded to the 10th of a second, depending on the rules then in place.

From 1975, the IAAF accepted separate automatically electronically timed records for events up to 400 metres. Starting January 1, 1977, the IAAF required fully automatic timing to the hundredth of a second for these events.^[1]

Riitta Salin's 50.14 from 1974 was the fastest recorded result to that time.

*Koch's record of 47.60 still stands as the fastest 400m ever run by a woman, although this is controversial. As Yahoo! Sports summarized in 2025, leaked documents from East Germany "specified dosages and dates for Koch's alleged use of the steroid Oral-Turinabol. Despite that, Koch has denied using performance-enhancing drugs, telling the BBC in 2014 that she has 'a clear conscience.' ... Track and field's governing body can't remove Koch's record because she never tested positive for banned substances and because the World Anti-Doping Association's 10-year statute of limitations has long expired."^[3] Had Koch's record previously been removed or if she were to admit to using PEDs, which would allow for the record to be retroactively revoked, the new record in the women's 400m would be held by American Sydney McLaughlin-Levrone, a former hurdler, who recorded a 47.78 on 18 September 2025 at the World Athletics Championship in Tokyo.^[4]