2015 IAAF World Relays – Women's 4 × 400 metres relay

The women's 4 × 400 metres relay at the 2015 IAAF World Relays was held at the Thomas Robinson Stadium on 2–3 May.

Records
Prior to the competition, the records were as follows:

Schedule
All times are local times (UTC−4)

Heats
Qualification: First 2 of each heat (Q) plus the 2 fastest times (q) advanced to the final.

Final B
The final B was started at 20:20.

Final
The final was started at 20:32.