| Athletics 400 metres hurdles | |
|---|---|
 Women's 400m hurdles | |
| World records | |
| Men |  Karsten Warholm 45.94 (2021) |
| Women |  Sydney McLaughlin-Levrone 50.37
(2024) |
| Olympic records | |
| Men | Karsten Warholm 45.94 (2021) |
| Women | Sydney McLaughlin-Levrone 50.37 (2024) |
| World Championship records | |
| Men |  Alison dos Santos 46.29 (2022) |
| Women | Sydney McLaughlin-Levrone 50.68 (2022) |
The 400 metres hurdles is a track and field hurdling event. The event has been on the Olympic athletics programme since 1900 for men and since 1984 for women.
On a standard outdoor track, 400 metres is the length of the inside lane, once around the stadium. Runners stay in their lanes the entire way after starting out of the blocks and must clear ten hurdles that are evenly spaced around the track. The hurdles are positioned and weighted so that they fall forward if bumped into with sufficient force, to prevent injury to the runners. Although there is no longer any penalty for knocking hurdles over, runners prefer to clear them cleanly, as touching them during the race slows runners down.
The current men's and women's world record holders are Karsten Warholm with 45.94 seconds and Sydney McLaughlin-Levrone with 50.37 seconds. Compared to the 400 metres run, the hurdles race takes the men about three seconds longer and the women four seconds longer. Men clear hurdles that are 36 inches (91.4 cm) high, while women negotiate 30 inches (76.2 cm) barriers.
The 400 m hurdles was held for both sexes at the inaugural IAAF World Championships in Athletics. The first championship for women came at the 1980 World Championships in Athletics – being held as a one-off due to the lack of a race at the 1980 Summer Olympics.