2021 World Athletics Relays – Mixed 2 × 2 × 400 metres relay

The Mixed 2 x 2 x 400 metres relay at the 2021 World Athletics Relays was held at Silesian Stadium on 1 May. It was the second time that this event was held at the World Athletics Relays, after being first held in 2019. Each team had to comprise one man and one woman, who would each run twice, but could be lined up in any order.

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