1999 IAAF World Indoor Championships – Women's 400 metres

The women's 400 metres event at the 1999 IAAF World Indoor Championships was held on March 5–7.

Heats
First 2 of each heat (Q) and next 4 fastest (q) qualified for the semifinals.

Semifinals
First 2 of each semifinal (Q) and the next 2 fastest (q) qualified for the final.