Athletics at the 1984 Summer Olympics – Women's 400 metres

These are the official results of the Women's 400 metres event at the 1984 Summer Olympics in Los Angeles, California. The final was held on August 6, 1984.

Final
Held on August 6, 1984

Semifinals

 * Held on August 5, 1984

Round one

 * Held on August 4, 1984