2021 World Athletics U20 Championships – Men's 4 × 100 metres relay

The men's 4 × 100 metres relay at the 2021 World Athletics U20 Championships was held at the Kasarani Stadium on 21 and 22 August.

Heats
Qualification: First 3 of each heat ( Q ) plus the 2 fastest times ( q ) qualified for the final.

Final
The final was held on 22 August at 16:46.