The Women's 400 metres event at the 2013 European Athletics U23 Championships was held in Tampere, Finland, at Ratina Stadium on 11 and 13 July.
| Gold | Lénora Guion-Firmin | |
| Silver | Mirela Lavric | |
| Bronze | Justyna Święty |
13 July 2013
| Rank | Name | Nationality | Lane | Reaction Time | Time | Notes | |||
|---|---|---|---|---|---|---|---|---|---|
| align=left | align=left | | 3 | 0.159 | 51.68 | PB | |||
| align=left | align=left | | 5 | 0.176 | 52.06 | PB | |||
| align=left | align=left | | 6 | 0.183 | 52.22 | PB | |||
| 4 | align=left | align=left | | 4 | 0.180 | 52.28 | PB | ||
| 5 | align=left | align=left | | 7 | 0.199 | 52.44 | PB | ||
| 6 | align=left | align=left | 1 | 0.204 | 52.52 | ||||
| 7 | align=left | align=left |  | 2 | 0.179 | 52.66 | PB | ||
| 8 | align=left | align=left | 8 | 0.187 | 53.97 |
Qualified: First 2 in each heat (Q) and 2 best performers (q) advance to the Final
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 52.27 | Q PB | ||
| 2 | align=left | align=left | | 52.45 | Q SB | ||
| 3 | align=left | align=left | 52.46 | q PB | |||
| 4 | align=left | align=left | | 52.76 | Q | ||
| 5 | align=left | align=left | | 52.78 | Q | ||
| 6 | align=left | align=left | | 52.80 | Q | ||
| 7 | align=left | align=left | | 52.83 | q PB | ||
| 8 | align=left | align=left | 52.93 | Q PB | |||
| 9 | align=left | align=left |  | 53.45 | PB | ||
| 10 | align=left | align=left |  | 53.49 | |||
| 11 | align=left | align=left | | 53.65 | |||
| 12 | align=left | align=left | | 53.67 | |||
| 13 | align=left | align=left | 53.79 | ||||
| 14 | align=left | align=left | | 53.91 | PB | ||
| 15 | align=left | align=left |  | 54.22 | |||
| 16 | align=left | align=left |  | 54.45 | |||
| 17 | align=left | align=left |  | 54.63 | SB | ||
| 18 | align=left | align=left | 54.79 | ||||
| 19 | align=left | align=left | | 55.07 | |||
| 20 | align=left | align=left |  | 59.49 | SB |
11 July 2013 / 19:35
| Rank | Name | Nationality | Lane | Reaction Time | Time | Notes | |||
|---|---|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 3 | 0.195 | 52.76 | Q | ||
| 2 | align=left | align=left | | 4 | 0.184 | 52.78 | Q | ||
| 3 | align=left | align=left | | 6 | 0.200 | 52.83 | q PB | ||
| 4 | align=left | align=left | | 7 | 0.267 | 53.67 | |||
| 5 | align=left | align=left | | 5 | 0.205 | 54.22 | |||
| 6 | align=left | align=left | | 2 | 0.206 | 55.07 |
11 July 2013 / 19:43
| Rank | Name | Nationality | Lane | Reaction Time | Time | Notes | |||
|---|---|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 2 | 0.186 | 52.27 | Q PB | ||
| 2 | align=left | align=left | | 3 | 0.186 | 52.45 | Q SB | ||
| 3 | align=left | align=left | 7 | 0.187 | 52.46 | q PB | |||
| 4 | align=left | align=left | 6 | 0.162 | 53.79 | ||||
| 5 | align=left | align=left | | 4 | 0.211 | 54.45 | |||
| 6 | align=left | align=left | 5 | 0.177 | 54.79 | ||||
| 7 | align=left | align=left | | 8 | 0.259 | 59.49 | SB |
11 July 2013 / 19:51
| Rank | Name | Nationality | Lane | Reaction Time | Time | Notes | |||
|---|---|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 8 | 0.164 | 52.80 | Q | ||
| 2 | align=left | align=left | 5 | 0.178 | 52.93 | Q PB | |||
| 3 | align=left | align=left | | 4 | 0.182 | 53.45 | PB | ||
| 4 | align=left | align=left | | 2 | 0.210 | 53.49 | |||
| 5 | align=left | align=left | | 3 | 0.202 | 53.65 | |||
| 6 | align=left | align=left | | 6 | 0.159 | 53.91 | PB | ||
| 7 | align=left | align=left | | 7 | 0.166 | 54.63 | SB |
According to an unofficial count, 20 athletes from 13 countries participated in the event.