# 2021 European Athletics U23 Championships – Women's 400 metres

The women's 400 metres event at the 2021 European Athletics U23 Championships was held in Tallinn, Estonia, at Kadriorg Stadium on 8, 9 and 10 July.

## Records

Prior to the competition, the records were as follows:
| European U23 record | Marita Koch (GDR) | 48.60 | Turin, Italy | 4 August 1979 |
| Championship U23 record | Olga Zaytseva (RUS) | 50.72 | Erfurt, Germany | 16 July 2005 |

## Results
### Round 1

Qualification rule: First 3 in each heat (Q) and the next 4 fastest (q) advance to the Semi-Finals.
| Rank | Heat | Name | Nationality | Time | Notes |
| 1 | 1 | Silke Lemmens | Switzerland | 52.73 | Q, NU23R |
| 2 | 3 | Lada Vondrová | Czech Republic | 53.03 | Q |
| 3 | 1 | Barbora Malíková | Czech Republic | 53.09 | Q |
| 4 | 4 | Sokhna Lacoste | France | 53.26 | Q |
| 5 | 4 | Mona Mayer | Germany | 53.32 | Q |
| 6 | 3 | Asnāte Kalniņa | Latvia | 53.44 | Q, PB |
| 7 | 4 | Mette Baas | Finland | 53.46 | Q |
| 8 | 3 | Anna Polinari | Italy | 53.53 | Q |
| 9 | 4 | Samantha Zago | Italy | 53.62 | q |
| 10 | 3 | Luna Thiel | Germany | 53.63 | q |
| 11 | 2 | Alessandra Bonora | Italy | 53.69 | Q |
| 12 | 2 | Kinga Gacka | Poland | 54.04 | Q |
| 13 | 1 | Andrea Jiménez | Spain | 54.09 | Q |
| 14 | 3 | Aleksandra Formella | Poland | 54.10 | q |
| 15 | 3 | Maryana Shostak | Ukraine | 54.17 | q, SB |
| 16 | 1 | Veronika Drljačić | Croatia | 54.28 | |
| 17 | 2 | Yasmin Liverpool | Great Britain | 54.45 | Q |
| 18 | 2 | Asteria Uzo Limai | Belarus | 54.82 | |
| 19 | 4 | Veronica Vancardo | Switzerland | 54.89 | |
| 20 | 2 | Věra Holubářová | Czech Republic | 54.92 | |
| 21 | 2 | Julia Niederberger | Switzerland | 54.96 | =PB |
| 22 | 1 | Elif Polat | Turkey | 55.11 | |
| 23 | 4 | Josefine Tomine Eriksen | Norway | 55.77 | |
| 24 | 1 | Hanna Répássy | Hungary | 55.86 | |
| 25 | 2 | Noragia Catherine Johnson | Greece | 56.67 | |
| 26 | 3 | Natália Bučičová | Slovakia | 59.63 | |
| | 1 | Alina Luchshava | Belarus | DNS | DNS |

### Semifinals

Qualification rule: First 3 in each heat (Q) and the next 2 fastest (q) advance to the Final.
| Rank | Heat | Name | Nationality | Time | Notes |
| 1 | 2 | Barbora Malíková | Czech Republic | 52.41 | Q |
| 2 | 1 | Lada Vondrová | Czech Republic | 52.58 | Q |
| 3 | 1 | Sokhna Lacoste | France | 52.71 | Q |
| 4 | 2 | Silke Lemmens | Switzerland | 53.07 | Q |
| 5 | 1 | Mona Mayer | Germany | 53.27 | Q |
| 6 | 1 | Samantha Zago | Italy | 53.48 | q |
| 7 | 2 | Mette Baas | Finland | 53.53 | Q |
| 8 | 2 | Kinga Gacka | Poland | 53.55 | q |
| 9 | 1 | Andrea Jiménez | Spain | 53.67 | |
| 10 | 1 | Asnāte Kalniņa | Latvia | 53.90 | |
| 11 | 1 | Anna Polinari | Italy | 54.07 | |
| 12 | 2 | Alessandra Bonora | Italy | 54.14 | |
| 13 | 2 | Luna Thiel | Germany | 54.35 | |
| 14 | 2 | Maryana Shostak | Ukraine | 54.39 | |
| 15 | 1 | Aleksandra Formella | Poland | 54.41 | |
| 16 | 2 | Yasmin Liverpool | Great Britain | 56.27 | |

### Final

| Rank | Lane | Name | Nationality | Time | Notes |
| | 6 | Lada Vondrová | Czech Republic | 51.19 | PB |
| | 3 | Barbora Malíková | Czech Republic | 51.23 | =PB |
| | 5 | Silke Lemmens | Switzerland | 52.09 | NU23R |
| 4 | 4 | Sokhna Lacoste | France | 52.19 | PB |
| 5 | 7 | Mona Mayer | Germany | 52.25 | PB |
| 6 | 2 | Kinga Gacka | Poland | 52.53 | PB |
| 7 | 8 | Mette Baas | Finland | 53.26 | PB |
| 8 | 1 | Samantha Zago | Italy | 53.57 | |