| Start Time: 21:00. Temperature: 24 °C, Humidity: 78%, Conditions: Cloudy. |   
| Final |   | time |   | gap | O | bib |  | 1. Matthew Centrowitz, Jr. |   United States | 3:50.00 |   |   | 4 | 3056 |  | 2. Taoufik Makhloufi |   Algeria | 3:50.11 |   | +0.11s | 7 | 2009 |  | 3. Nick Willis |   New Zealand | 3:50.24 |   | +0.24s | 10 | 2814 |  | 4. Ayanleh Souleiman |   Djibouti | 3:50.29 |   | +0.29s | 1 | 2317 |  | 5. Abdalaati Iguider |   Morocco | 3:50.58 |   | +0.58s | 2 | 2744 |  | 6. Asbel Kiprop |   Kenya | 3:50.87 |   | +0.87s | 3 | 2682 |  | 7. David Bustos |   Spain | 3:51.06 |   | +1.06s | 13 | 2349 |  | 8. Ben Blankenship |   United States | 3:51.09 |   | +1.09s | 11 | 3051 |  | 9. Ryan Gregson |   Australia | 3:51.39 |   | +1.39s | 6 | 2038 |  | 10.Nathan Brannen |   Canada | 3:51.45 |   | +1.45s | 9 | 2191 |  | 11.Ronald Musagala |   Uganda | 3:51.68 |   | +1.68s | 5 | 3022 |  | 12.Charlie Grice |   Great Britain | 3:51.73 |   | +1.73s | 8 | 2458 |  | 13.Ronald Kwemoi |   Kenya | 3:56.76 |   | +6.76s | 12 | 2689 |   
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| 42 Competitors from 26 Nations. Venue: Estádio Olímpico João Havelange Cap: 46,931. |  | World Record: Hicham El Guerrouj, Morocco 3:26.00 Rome, Italy 14 July 1998 |  | Olympic Record: Noah Ngeny, Kenya 3:32.07 Sydney, Australia 29 September 2000 |   
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 Semi-Finals - Thursday, 18th August 20:45 |  | First 5 and Best 2 times advanced to Final.  |   
| Semi 1 |   | time |   |  | 1. Asbel Kiprop |   Kenya | 3:39.73 | Q |  | 2. Taoufik Makhloufi |   Algeria | 3:39.88 | Q |  | 3. Nicholas Willis |   New Zealand | 3:39.96 | Q |  | 4. Ben Blankenship |   United States | 3:39.99 | Q |  | 5. Charlie Grice |   Great Britain | 3:40.05 | Q |  | 6. Abdalaati Iguider |   Morocco | 3:40.11 | q |  | 7. Nathan Brannen |   Canada | 3:40.20 | q |  | 8. Benson Kiplagat Seurei |   Bahrain | 3:40.53 |   |  | 9. Jakub Holusa |   Czechia | 3:40.83 |   |  | 10.Dawit Wolde |   Ethiopia | 3:41.42 |   |  | 11.Henrik Ingebrigtsen |   Norway | 3:42.51 |   |  | 12.Pieter-Jan Hannes |   Belgium | 3:43.71 |   |  | 13.Brahim Kaazouzi |   Morocco | 3:48.66 |   |   
| Semi 2 |   | time |   |  | 1. Ronald Kwemoi |   Kenya | 3:39.42 | Q |  | 2. Ayanleh Souleiman |   Djibouti | 3:39.46 | Q |  | 3. Matthew Centrowitz |   United States | 3:39.61 | Q |  | 4. Ryan Gregson |   Australia | 3:40.02 | Q |  | 5. Ronald Musagala |   Uganda | 3:40.37 | Q |  | 6. Mekonnen Gebremedhin |   Ethiopia | 3:40.69 |   |  | 7. Homiyu Tesfaye |   Germany | 3:40.76 |   |  | 8. Charles Philibert-Thiboutot |   Canada | 3:40.79 |   |  | 9. Fouad Elkaam |   Morocco | 3:40.93 |   |  | 10.Chris O'Hare |   Great Britain | 3:44.27 |   |  | 11.David Bustos |   Spain | 3:56.54 | qr |  | -. Robby Andrews |   United States | R163.4 | DQ |  | -. Elijah Manango |   Kenya | DNS |   |   
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  Heats - Tuesday, 16th August 10:30 |  | First 6 and Best 6 times advanced to Semi-Finals.  |   
| Heat 1 |   | time |   |  | 1. Asbel Kiprop |   Kenya | 3:38.97 | Q |  | 2. Ryan Gregson |   Australia | 3:39.13 | Q |  | 3. Ayanleh Souleiman |   Djibouti | 3:39.25 | Q |  | 4. Chris O'Hare |   Great Britain | 3:39.26 | Q |  | 5. Matthew Centrowitz |   United States | 3:39.31 | Q |  | 6. Fouad Elkaam |   Morocco | 3:39.51 | Q |  | 7. David Bustos |   Spain | 3:39.73 | q |  | 8. Charles Philibert-Thiboutot |   Canada | 3:40.04 | q |  | 9. Julian Matthews |   New Zealand | 3:40.40 |   |  | 10.Florian Carvalho |   France | 3:41.87 |   |  | 11.Thiago André |   Brazil | 3:44.42 |   |  | 12.Santino Kenyi |   South Sudan | 3:45.27 |   |  | 13.Saud Al-Zaabi |   UA Emirates | 4:02.35 |   |  | -. Aman Wote |   Ethiopia | DNS |   |   
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| Heat 2 |   | time |   |  | 1. Taoufik Makhloufi |   Algeria | 3:46.82 | Q |  | 2. Elijah Motonei Manangoi |   Kenya | 3:46.83 | Q |  | 3. Robby Andrews |   United States | 3:46.97 | Q |  | 4. Nathan Brannen |   Canada | 3:47.07 | Q |  | 5. Mekonnen Gebremedhin |   Ethiopia | 3:47.33 | Q |  | 6. Brahim Kaazouzi |   Morocco | 3:47.39 | Q |  | 7. Homiyu Tesfaye |   Germany | 3:47.44 | qr |  | 8. Hamish Carson |   New Zealand | 3:48.18 |   |  | 9. Adel Mechaal |   Spain | 3:48.41 |   |  | 10.Charlie Grice |   Great Britain | 3:48.51 | qr |  | 11.Paulo Lokoro |   Refugee OT | 4:03.96 |   |  | 12.Augusto Soares |   Timor-Leste | 4:11.35 | PB |  | -. Abdi Waiss Mouhyadin |   Djibouti | DNF |   |  | -. Filip Ingebrigtsen |   Norway | R163.2 | DQ |   
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