The men's 800 metres event at the 2002 World Junior Championships in Athletics was held in Kingston, Jamaica, at National Stadium on 16, 17 and 19 July.
| Gold | Alex Kipchirchir | |
| Silver | Salem Amer Al-Badri | |
| Bronze | David Fiegen |
19 July
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| align=left | align=left | | 1:46.59 | ||||
| align=left | align=left | | 1:46.63 | ||||
| align=left | align=left | | 1:46.66 | ||||
| 4 | align=left | align=left | | 1:46.86 | |||
| 5 | align=left | align=left | 1:47.20 | ||||
| 6 | align=left | align=left |  | 1:47.44 | |||
| 7 | align=left | align=left |  | 1:48.18 | |||
| 8 | align=left | align=left | | 1:56.73 |
17 July
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 1:49.55 | Q | ||
| 2 | align=left | align=left | | 1:49.61 | Q | ||
| 3 | align=left | align=left | | 1:49.72 | Q | ||
| 4 | align=left | align=left |  | 1:49.99 | |||
| 5 | align=left | align=left | 1:50.17 | ||||
| 6 | align=left | align=left |  | 1:50.29 | |||
| 7 | align=left | align=left | 1:50.96 | ||||
| 8 | align=left | align=left |  | 1:52.08 | |||
| 9 | align=left | align=left |  | 1:53.36 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 1:46.36 | Q | |||
| 2 | align=left | align=left | | 1:46.40 | Q | ||
| 3 | align=left | align=left | | 1:46.82 | Q | ||
| 4 | align=left | align=left | | 1:46.92 | q | ||
| 5 | align=left | align=left | | 1:48.46 | q | ||
| 6 | align=left | align=left | | 1:49.83 | |||
| 7 | align=left | align=left |  | 1:52.37 | |||
| 8 | align=left | align=left | | 1:53.67 |
16 July
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 1:48.93 | Q | ||
| 2 | align=left | align=left | | 1:49.03 | Q | ||
| 3 | align=left | align=left | | 1:49.21 | q | ||
| 4 | align=left | align=left |  | 1:52.16 | |||
| 5 | align=left | align=left | 1:56.61 | ||||
| 6 | align=left | align=left |  | 1:58.21 | |||
| 7 | align=left | align=left |  | 2:01.16 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 1:48.26 | Q | ||
| 2 | align=left | align=left | 1:48.82 | Q | |||
| 3 | align=left | align=left | | 1:49.45 | q | ||
| 4 | align=left | align=left | | 1:50.23 | q | ||
| 5 | align=left | align=left | 1:52.15 | ||||
| 6 | align=left | align=left |  | 1:52.84 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 1:49.86 | Q | ||
| 2 | align=left | align=left | | 1:50.10 | Q | ||
| 3 | align=left | align=left | | 1:50.15 | q | ||
| 4 | align=left | align=left | 1:50.79 | ||||
| 5 | align=left | align=left | 1:51.00 | ||||
| 6 | align=left | align=left | | 1:51.06 | |||
| 7 | align=left | align=left | 1:56.74 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 1:49.63 | Q | ||
| 2 | align=left | align=left | 1:50.13 | Q | |||
| 3 | align=left | align=left | 1:50.48 | ||||
| 4 | align=left | align=left | 1:50.62 | ||||
| 5 | align=left | align=left |  | 1:50.93 | |||
| 6 | align=left | align=left | 1:51.25 | ||||
| 7 | align=left | align=left | 1:51.86 | q |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 1:49.28 | Q | ||
| 2 | align=left | align=left | | 1:49.45 | Q | ||
| 3 | align=left | align=left | | 1:49.62 | q | ||
| 4 | align=left | align=left | | 1:50.17 | q | ||
| 5 | align=left | align=left | | 1:50.57 | |||
| 6 | align=left | align=left |  | 1:53.65 | |||
| 7 | align=left | align=left |  | 2:09.88 |
According to an unofficial count, 34 athletes from 26 countries participated in the event.