Athletics at the 1970 British Commonwealth Games – Women's 400 metres

The women's 400 metres event at the 1970 British Commonwealth Games was held on 22 and 23 July at the Meadowbank Stadium in Edinburgh, Scotland. It was the first time that the metric distance was contested at the Games replacing the 440 yards event.

The winning margin was an enormous 2.64 seconds which as of 2024 remains the only time the women's 400 metres was won by more than two seconds at these games.

Heats
Qualification: First 4 in each semifinal (Q) qualify directly for the final.