The men's 800 metres event at the 2015 European Athletics U23 Championships was held in Tallinn, Estonia, at Kadriorg Stadium on 10, 11 and 12 July.
| Gold | Artur Kuciapski | |
| Silver | Saúl Ordóñez | |
| Bronze | Žan Rudolf |
12 July
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| align=left | align=left | | 1:48.11 | ||||
| align=left | align=left | | 1:48.23 | ||||
| align=left | align=left | 1:48.47 | |||||
| 4 | align=left | align=left | 1:48.62 | ||||
| 5 | align=left | align=left |  | 1:48.64 | |||
| 6 | align=left | align=left |  | 1:48.79 | |||
| 7 | align=left | align=left | | 1:49.14 | |||
| 8 | align=left | align=left | | 1:50.42 |
11 July
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 1:48.42 | Q | ||
| 2 | align=left | align=left | | 1:48.50 | Q | ||
| 3 | align=left | align=left | 1:48.57 | Q | |||
| 4 | align=left | align=left | | 1:48.65 | q | ||
| 5 | align=left | align=left | | 1:48.74 | q | ||
| 6 | align=left | align=left |  | 1:49.81 | |||
| 7 | align=left | align=left |  | 1:49.88 | |||
| 8 | align=left | align=left | | 1:52.40 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 1:49.89 | Q | |||
| 2 | align=left | align=left | | 1:49.91 | Q | ||
| 3 | align=left | align=left | | 1:49.94 | Q | ||
| 4 | align=left | align=left | 1:50.04 | ||||
| 5 | align=left | align=left |  | 1:50.18 | |||
| 6 | align=left | align=left | | 1:50.31 | |||
| 7 | align=left | align=left | | 1:50.37 | |||
| align=left | align=left | | DNS |
10 July
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 1:49.29 | Q | ||
| 2 | align=left | align=left | | 1:49.34 | Q | ||
| 3 | align=left | align=left | | 1:49.35 | Q | ||
| 4 | align=left | align=left | | 1:49.60 | q | ||
| 5 | align=left | align=left | | 1:49.93 | q | ||
| 6 | align=left | align=left | 1:49.95 | q | |||
| 7 | align=left | align=left |  | 1:50.08 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 1:49.61 | Q | ||
| 2 | align=left | align=left | | 1:50.00 | Q | ||
| 3 | align=left | align=left | | 1:50.04 | Q | ||
| 4 | align=left | align=left |  | 1:50.28 | |||
| 5 | align=left | align=left | 1:50.43 | ||||
| 6 | align=left | align=left | | 1:50.51 | |||
| 7 | align=left | align=left | | 1:51.08 | |||
| 8 | align=left | align=left |  | 1:51.62 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 1:49.17 | Q | |||
| 2 | align=left | align=left | | 1:49.54 | Q | ||
| 3 | align=left | align=left | | 1:49.57 | Q | ||
| 4 | align=left | align=left | | 1:49.93 | q | ||
| 5 | align=left | align=left |  | 1:50.04 | |||
| 6 | align=left | align=left |  | 1:50.06 | |||
| 7 | align=left | align=left |  | 1:50.13 | |||
| 8 | align=left | align=left | 1:54.54 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 1:52.88 | Q | |||
| 2 | align=left | align=left | | 1:52.91 | Q | ||
| 2 | align=left | align=left | | 1:52.91 | Q | ||
| 4 | align=left | align=left | 1:52.97 | ||||
| 5 | align=left | align=left | | 1:53.53 | |||
| 6 | align=left | align=left | | 1:54.45 | |||
| 7 | align=left | align=left | | 1:54.45 |
According to an unofficial count, 30 athletes from 18 countries participated in the event.