# 2021 World Athletics U20 Championships – Men's 800 metres

The men's 800 metres at the 2021 World Athletics U20 Championships was held at the Kasarani Stadium on 19, 21 and 22 August.

## Records

Standing records prior to the 2021 World Athletics U20 Championships :
| World U20 Record | Nijel Amos (BOT) | 1:41.73 | London, United Kingdom | 9 August 2012 |
| Championship Record | Nijel Amos (BOT) | 1:43.79 | Barcelona, Spain | 15 July 2012 |
| World U20 Leading | Max Burgin (GBR) | 1:44.14 | Ostrava, Czech Republic | 19 May 2021 |

## Results
### Heats

Qualification: First 3 of each heat (Q) and the 4 fastest times (q) qualified for the semifinals.
| Rank | Heat | Name | Nationality | Time | Note |
| 1 | 3 | Emmanuel Wanyonyi | Kenya | 1:46.51 | Q |
| 2 | 1 | Noah Kibet | Kenya | 1:46.70 | Q |
| 3 | 3 | Yanis Meziane | France | 1:47.28 | Q, PB |
| 4 | 1 | Jakub Davidík | Czech Republic | 1:47.84 | Q |
| 5 | 4 | Mohamed Ali Gouaned | Algeria | 1:48.83 | Q |
| 6 | 2 | Kacper Lewalski | Poland | 1:48.84 | Q |
| 7 | 2 | Abdullahi Hassan | Canada | 1:49.09 | Q |
| 8 | 1 | Heithem Chenitef | Algeria | 1:49.19 | Q, PB |
| 9 | 3 | Daniel Wolde | Ethiopia | 1:49.20 | Q |
| 10 | 3 | Handal Roban | Saint Vincent and the Grenadines | 1:49.41 | q, NU20R |
| 11 | 2 | Chevonne Hall | Jamaica | 1:49.47 | Q |
| 12 | 2 | Abdullah Al-Yaari | Yemen | 1:49.65 | q |
| 13 | 2 | El Hafez Mahadi | Qatar | 1:49.68 | q |
| 14 | 4 | Leonardo Santos | Brazil | 1:49.76 | Q |
| 15 | 3 | Abednico Choba | South Africa | 1:50.20 | q |
| 16 | 4 | Paul Anselmini | France | 1:50.23 | Q |
| 17 | 1 | Anu Kumar | India | 1:50.26 | |
| 18 | 2 | Husain Mohsin Al-Farsi | Oman | 1:50.34 | PB |
| 19 | 1 | David Garcia | Portugal | 1:50.92 | |
| 20 | 4 | Nikita Yegorov | Authorised Neutral Athletes | 1:51.80 | |
| 21 | 4 | Matthew Erickson | Canada | 1:52.38 | |
| 22 | 1 | Fithawi Zaid | Eritrea | 1:52.46 | |
| 23 | 4 | Remmy Ng'andu | Zambia | 1:52.48 | |
| 24 | 2 | Masresha Costa | Italy | 1:52.71 | |
| 25 | 3 | Mark Fandly | Romania | 1:52.81 | |
| 26 | 4 | Francesco Pernici | Italy | 1:53.35 | |
| 27 | 3 | Osaze Demund | United States Virgin Islands | 1:58.50 | PB |
| 28 | 4 | Mohamed Mustafa | Sudan | 1:59.55 | PB |
| 29 | 3 | Aleksa Tomić | Serbia | 2:06.05 | |
| | 1 | Ermias Girma | Ethiopia | DQ | TR17.3.1 |

### Semifinals

Qualification: First 3 of each heat (Q) and the 2 fastest times (q) qualified for the final.
| Rank | Heat | Name | Nationality | Time | Note |
| 1 | 1 | Emmanuel Wanyonyi | Kenya | 1:46.15 | Q |
| 2 | 2 | Noah Kibet | Kenya | 1:46.47 | Q |
| 3 | 2 | Jakub Davidík | Czech Republic | 1:46.59 | Q, NU20R |
| 4 | 2 | Abdullahi Hassan | Canada | 1:46.89 | Q |
| 5 | 2 | Kacper Lewalski | Poland | 1:47.31 | q |
| 6 | 1 | Mohamed Ali Gouaned | Algeria | 1:47.35 | Q |
| 7 | 1 | Daniel Wolde | Ethiopia | 1:47.53 | Q |
| 8 | 1 | Paul Anselmini | France | 1:47.81 | q, PB |
| 9 | 2 | Abednico Choba | South Africa | 1:48.23 | PB |
| 10 | 1 | Handal Roban | Saint Vincent and the Grenadines | 1:48.37 | NU20R |
| 11 | 2 | Chevonne Hall | Jamaica | 1:48.50 | PB |
| 12 | 1 | Leonardo Santos | Brazil | 1:48.78 | |
| 13 | 2 | Heithem Chenitef | Algeria | 1:49.57 | |
| 14 | 1 | El Hafez Mahadi | Qatar | 1:49.84 | |
| 15 | 1 | Abdullah Al-Yaari | Yemen | 1:53.24 | |
| | 2 | Yanis Meziane | France | DNF | |

### Final

The final was held on 22 August at 15:31.
| Rank | Lane | Name | Nationality | Time | Note |
| | 3 | Emmanuel Wanyonyi | Kenya | 1:43.76 | CR, WU20L |
| | 6 | Mohamed Ali Gouaned | Algeria | 1:44.45 | NU20R |
| | 5 | Noah Kibet | Kenya | 1:44.88 | PB |
| 4 | 7 | Jakub Davidík | Czech Republic | 1:46.07 | NU20R |
| 5 | 2 | Daniel Wolde | Ethiopia | 1:48.62 | |
| 6 | 8 | Kacper Lewalski | Poland | 1:49.40 | |
| 7 | 4 | Abdullahi Hassan | Canada | 1:50.07 | |
| 8 | 1 | Paul Anselmini | France | 1:53.70 | |