The men's 800 metres event at the 2019 Summer Universiade was held on 11, 12 and 13 July at the Stadio San Paolo in Naples.
| width=200 bgcolor=gold | Gold | width=200 bgcolor=silver | Silver | width=200 bgcolor=CC9966 | Bronze |
| Mohamed Belbachir | Moad Zahafi | Lukáš Hodboď |
Qualification: First 4 in each heat (Q) and next 4 fastest (q) qualified for the semifinals.[1]
| Rank | Heat | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 1 | 3 | 1:49.98 | Q, SB | |||
| 2 | 3 | 1:49.99 | Q | |||
| 3 | 2 | 1:50.27 | Q | |||
| 4 | 2 | 1:50.51 | Q | |||
| 5 | 4 | 1:50.70 | Q | |||
| 6 | 2 | 1:50.72 | Q | |||
| 7 | 3 | 1:50.77 | Q | |||
| 8 | 3 | 1:50.90 | Q | |||
| 9 | 2 | 1:50.92 | Q | |||
| 10 | 1 | 1:51.05 | Q | |||
| 11 | 1 | 1:51.22 | Q | |||
| 12 | 2 | 1:51.23 | q, PB | |||
| 13 | 1 | 1:51.54 | Q | |||
| 14 | 4 | 1:51.61 | Q | |||
| 15 | 1 | 1:51.74 | Q | |||
| 16 | 5 | 1:51.82 | Q | |||
| 17 | 4 | 1:51.84 | Q | |||
| 18 | 5 | 1:51.85 | Q | |||
| 19 | 3 | 1:52.04 | q | |||
| 20 | 5 | 1:52.09 | Q | |||
| 21 | 5 | 1:52.20 | Q | |||
| 22 | 2 | 1:52.27 | q, SB | |||
| 23 | 2 | 1:52.43 | q | |||
| 24 | 5 | 1:52.45 | PB | |||
| 25 | 3 | 1:52.49 | PB | |||
| 26 | 1 | 1:52.70 | ||||
| 27 | 5 | 1:52.75 | ||||
| 28 | 3 | 1:52.83 | ||||
| 29 | 5 | 1:52.85 | ||||
| 30 | 1 | 1:52.95 | ||||
| 31 | 4 | 1:53.44 | Q | |||
| 32 | 4 | 1:54.09 | ||||
| 33 | 4 | 1:54.22 | PB | |||
| 34 | 1 | 2:01.06 | SB | |||
| 35 | 3 | 2:20.38 | ||||
| 5 | ||||||
| 4 |
Qualification: First 2 in each heat (Q) and next 2 fastest (q) qualified for the final.[2]
| Rank | Heat | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 1 | 2 | 1:47.63 | Q | |||
| 2 | 3 | 1:47.86 | Q | |||
| 3 | 2 | 1:48.02 | Q | |||
| 4 | 3 | 1:48.11 | Q, SB | |||
| 5 | 2 | 1:48.14 | q | |||
| 6 | 2 | 1:48.68 | q | |||
| 7 | 2 | 1:48.90 | PB | |||
| 8 | 2 | 1:49.00 | SB | |||
| 9 | 3 | 1:49.28 | ||||
| 10 | 3 | 1:49.49 | ||||
| 11 | 2 | 1:49.50 | PB | |||
| 12 | 1 | 1:49.54 | Q | |||
| 13 | 1 | 1:49.76 | Q | |||
| 14 | 1 | 1:49.76 | ||||
| 15 | 1 | 1:49.98 | ||||
| 16 | 3 | 1:50.27 | ||||
| 17 | 1 | 1:50.53 | ||||
| 18 | 1 | 1:50.90 | ||||
| 19 | 2 | 1:50.95 | ||||
| 20 | 1 | 1:51.17 | PB | |||
| 21 | 3 | 1:51.25 | ||||
| 22 | 3 | 1:51.43 | ||||
| 23 | 1 | 1:53.30 | ||||
| 3 |
| Rank | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|
| 1:47.02 | |||||
| 1:47.64 | |||||
| 1:47.97 | SB | ||||
| 4 | 1:48.08 | SB | |||
| 5 | 1:48.58 | SB | |||
| 6 | 1:50.11 | ||||
| R163.3a[4] | |||||
| R163.3a |