The 400 metres hurdles at the Summer Olympics is the longest hurdling event held at the multi-sport event. The men's 400 m hurdles has been present on the Olympic athletics programme since 1900, with a sole gap at the 1912 Summer Olympics. The women's event was added to the programme over eighty years later, at the 1984 Olympics. It is the most prestigious 400 m hurdles race at elite level.