The men's 800 metres at the 2007 World Championships in Athletics was held at the Nagai Stadium on 30, 31 August and 2 September.
| width=200 bgcolor=gold | Gold | width=200 bgcolor=silver | Silver | width=200 bgcolor=CC9966 | Bronze |
| Alfred Kirwa Yego | Gary Reed | Yuriy Borzakovskiy |
Prior to the competition, the following records were as follows.
| World record | 1:41.11 | Cologne, Germany | 24 August 1997 | ||
| Championship record | 1:43.06 | Rome, Italy | 1 September 1987 | ||
| World leading | 1:43.74 | Monaco | 25 July 2007 |
| Date | Time | Round | |
|---|---|---|---|
| August 30, 2007 | 19:40 | Heats | |
| August 31, 2007 | 20:05 | Semifinals | |
| September 2, 2007 | 19:55 | Final |
Qualification: First 3 in each heat(Q) and the next 6 fastest(q) advance to the semifinals.
| Rank | Heat | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 6 | 1:45.25 | Q | ||||
| 4 | 1:45.52 | Q, SB | ||||
| 3 | 1:45.56 | Q | ||||
| 5 | 1:45.58 | Q | ||||
| 3 | 1:45.64 | Q, SB | ||||
| 3 | 1:45.66 | Q | ||||
| 4 | 1:45.66 | Q | ||||
| 6 | 1:45.68 | Q | ||||
| 4 | 1:45.72 | Q | ||||
| 10 | 3 | 1:45.77 | q | |||
| 11 | 4 | 1:45.78 | q | |||
| 12 | 5 | 1:45.79 | Q | |||
| 13 | 5 | 1:45.79 | Q | |||
| 14 | 6 | 1:45.85 | Q | |||
| 15 | 4 | 1:45.90 | q | |||
| 15 | 5 | 1:45.90 | q, SB | |||
| 17 | 1 | 1:46.00 | Q | |||
| 17 | 2 | 1:46.00 | Q | |||
| 19 | 2 | 1:46.02 | Q | |||
| 20 | 2 | 1:46.08 | Q | |||
| 21 | 1 | 1:46.16 | Q | |||
| 21 | 6 | 1:46.16 | q | |||
| 23 | 1 | 1:46.17 | Q | |||
| 24 | 5 | 1:46.20 | q | |||
| 25 | 6 | 1:46.24 | SB | |||
| 26 | 3 | 1:46.28 | ||||
| 27 | 4 | 1:46.33 | PB | |||
| 28 | 1 | 1:46.34 | ||||
| 29 | 2 | 1:46.35 | ||||
| 30 | 5 | 1:46.38 | ||||
| 31 | 3 | 1:46.43 | PB | |||
| 32 | 4 | 1:46.47 | ||||
| 33 | 6 | 1:46.53 | ||||
| 34 | 3 | 1:46.62 | ||||
| 35 | 1 | 1:46.73 | ||||
| 36 | 1 | 1:46.75 | ||||
| 37 | 3 | 1:46.81 | ||||
| 38 | 5 | 1:47.16 | PB | |||
| 39 | 2 | 1:47.23 | ||||
| 40 | 2 | 1:47.44 | ||||
| 41 | 2 | 1:47.72 | NR | |||
| 42 | 4 | 1:48.42 | ||||
| 43 | 6 | 1:48.95 | ||||
| 44 | 5 | 1:49.06 | ||||
| 45 | 6 | 1:56.45 | SB | |||
| 46 | 1 | 1:56.55 | ||||
| 1 | DNF | |||||
| 2 | DNS |
Qualification: First 2 in each semifinal (Q) and the next 2 fastest (q) advance to the final.
| Rank | Heat | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 1 | 1:44.54 | Q, SB | ||||
| 1 | 1:44.71 | Q | ||||
| 1 | 1:44.84 | q | ||||
| 2 | 1:44.92 | Q | ||||
| 2 | 1:45.11 | Q | ||||
| 3 | 1:45.12 | Q | ||||
| 3 | 1:45.20 | Q | ||||
| 3 | 1:45.23 | q | ||||
| 3 | 1:45.31 | |||||
| 10 | 2 | 1:45.36 | SB | |||
| 11 | 1 | 1:45.45 | ||||
| 12 | 2 | 1:45.59 | ||||
| 13 | 2 | 1:45.61 | ||||
| 14 | 1 | 1:45.95 | ||||
| 15 | 1 | 1:46.27 | ||||
| 16 | 2 | 1:46.41 | ||||
| 17 | 3 | 1:46.45 | ||||
| 18 | 1 | 1:46.49 | ||||
| 19 | 2 | 1:46.86 | ||||
| 20 | 3 | 1:47.39 | ||||
| 21 | 2 | 1:47.76 | ||||
| 22 | 3 | 1:48.04 | ||||
| 23 | 3 | 1:50.28 | ||||
| 24 | 1 | 1:51.31 |
| Rank | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|
| 1:47.09 | |||||
| 1:47.10 | |||||
| 1:47.39 | |||||
| 4 | 1:47.41 | ||||
| 5 | 1:47.42 | ||||
| 6 | 1:47.45 | ||||
| 7 | 1:47.52 | ||||
| 8 | 1:47.58 |