2017 European Athletics U23 Championships – Men's 400 metres

The men's 400 metres event at the 2017 European Athletics U23 Championships was held in Bydgoszcz, Poland, at Zdzisław Krzyszkowiak Stadium on 13, 14 and 15 July.

Heats
14 July

Qualification rule: First 3 (Q) and the next 4 fastest (q) qualified for the semifinals.

Semifinals
14 July

Qualification rule: First 3 (Q) and the next 2 fastest (q) qualified for the final.

Final
15 July