# Swimming at the 1984 Summer Olympics – Men's 100 metre breaststroke

The final of the men's 100 metre breaststroke event at the 1984 Summer Olympics was held in the McDonald's Olympic Swim Stadium in Los Angeles, California, on July 29, 1984.

## Records

Prior to this competition, the existing world and Olympic records were as follows.
| World record | John Moffet (USA) | 1:02.13 | Indianapolis, United States | 25 June 1984 |
| Olympic record | John Hencken (USA) | 1:03.11 | Montreal, Canada | 20 July 1976 |
The following records were established during the competition:
| Date | Round | Name | Nation | Time | Record |
| 29 July | Heat 7 | John Moffet | United States | 1:02.16 | OR |
| 29 July | Final A | Steve Lundquist | United States | 1:01.65 | WR |

## Results
### Heats

Rule: The eight fastest swimmers advance to final A (Q), while the next eight to final B (q).
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 7 | 4 | John Moffet | United States | 1:02.16 | Q, OR |
| 2 | 2 | 4 | Peter Evans | Australia | 1:02.87 | Q, OC |
| 3 | 5 | 5 | Brett Stocks | Australia | 1:03.46 | Q |
| 4 | 5 | 4 | Gerald Mörken | West Germany | 1:03.53 | Q |
| 5 | 6 | 4 | Steve Lundquist | United States | 1:03.55 | Q |
| 6 | 4 | 4 | Victor Davis | Canada | 1:03.63 | Q |
| 7 | 3 | 4 | Adrian Moorhouse | Great Britain | 1:04.06 | Q |
| 8 | 2 | 5 | Raffaele Avagnano | Italy | 1:04.09 | Q |
| 9 | 3 | 5 | Gianni Minervini | Italy | 1:04.37 | q |
| 10 | 1 | 4 | Peter Lang | West Germany | 1:04.40 | q |
| 11 | 6 | 5 | Pablo Restrepo | Colombia | 1:04.44 | q |
| 12 | 1 | 3 | Thomas Böhm | Austria | 1:04.60 | q, NR |
| 13 | 7 | 5 | Shigehiro Takahashi | Japan | 1:04.71 | q |
| 14 | 7 | 3 | Iain Campbell | Great Britain | 1:04.81 | q |
| 15 | 4 | 3 | Brett Austin | New Zealand | 1:04.83 | q, NR |
| 16 | 3 | 3 | Peter Berggren | Sweden | 1:04.95 | q |
| 17 | 7 | 2 | Jin Fu | China | 1:05.05 | |
| 18 | 2 | 3 | Enrique Romero | Spain | 1:05.19 | NR |
| 19 | 1 | 5 | Marco Veilleux | Canada | 1:05.34 | |
| 20 | 4 | 5 | Étienne Dagon | Switzerland | 1:05.37 | |
| 21 | 4 | 6 | Jan-Erick Olsen | Norway | 1:05.43 | NR |
| 22 | 3 | 6 | Eyal Stigman | Israel | 1:05.63 | NR |
| 23 | 2 | 6 | Felix Morf | Switzerland | 1:05.89 | |
| 24 | 1 | 2 | Victor Ruberry | Bermuda | 1:05.96 | NR |
| 24 | 6 | 6 | Luiz Carvalho | Brazil | 1:05.96 | |
| 26 | 3 | 2 | Manuel Gutiérrez | Panama | 1:06.07 | |
| 27 | 5 | 6 | Kenji Watanabe | Japan | 1:06.10 | |
| 28 | 5 | 3 | Paul Newallo | Trinidad and Tobago | 1:06.12 | NR |
| 29 | 6 | 3 | Martti Järventaus | Finland | 1:06.21 | |
| 30 | 7 | 6 | Gerhard Prohaska | Austria | 1:06.41 | |
| 31 | 5 | 2 | Eduardo Morillo | Mexico | 1:06.82 | |
| 32 | 7 | 7 | Francisco Guanco | Philippines | 1:07.55 | |
| 33 | 1 | 7 | Tryggvi Helgason | Iceland | 1:07.71 | NR |
| 34 | 1 | 6 | Julio César Falón | Argentina | 1:07.80 | |
| 34 | 4 | 6 | Alexandre Yokochi | Portugal | 1:07.80 | |
| 36 | 6 | 7 | Jairulla Jaitulla | Philippines | 1:08.00 | |
| 37 | 2 | 2 | Watt Kam Sing | Hong Kong | 1:08.07 | |
| 38 | 7 | 1 | Árni Sigurðsson | Iceland | 1:08.52 | |
| 39 | 5 | 7 | Li Khai Kam | Hong Kong | 1:08.75 | |
| 40 | 4 | 7 | Jorge Henao | Venezuela | 1:09.01 | |
| 41 | 3 | 7 | Oscar Ortigosa | Peru | 1:09.07 | |
| 42 | 6 | 1 | Oon Jin Teik | Singapore | 1:09.23 | |
| 43 | 2 | 7 | Ayman Nadim | Egypt | 1:09.51 | |
| 44 | 5 | 1 | Fernando Marroquin | Guatemala | 1:09.73 | |
| 45 | 4 | 1 | Harrell Woolard | Virgin Islands | 1:11.17 | |
| 46 | 3 | 1 | Brian Farlow | Virgin Islands | 1:11.27 | |
| 47 | 2 | 1 | Ahmad Al-Hahdoud | Kuwait | 1:13.01 | |
| 48 | 1 | 1 | Michele Piva | San Marino | 1:16.21 | |
| 49 | 7 | 8 | Isaac Atish Wa-El | Kuwait | 1:16.51 | |
| 50 | 6 | 8 | Amine El-Domyati | Lebanon | 1:19.10 | |
| | 5 | 8 | Salvador Corelo | Honduras | DSQ | |
| | 6 | 2 | Wang Lin | China | DSQ | |

### Finals
#### Final B

| Rank | Lane | Name | Nationality | Time |
| 9 | 4 | Gianni Minervini | Italy | 1:03.99 |
| 10 | 2 | Shigehiro Takahashi | Japan | 1:04.41 |
| 11 | 5 | Peter Lang | West Germany | 1:04.43 |
| 12 | 3 | Pablo Restrepo | Colombia | 1:04.79 |
| 13 | 6 | Thomas Böhm | Austria | 1:04.99 |
| 14 | 7 | Iain Campbell | Great Britain | 1:05.02 |
| 15 | 1 | Brett Austin | New Zealand | 1:05.49 |
| 16 | 8 | Peter Berggren | Sweden | 1:05.66 |

#### Final A

| Rank | Lane | Name | Nationality | Time | Notes |
| | 2 | Steve Lundquist | United States | 1:01.65 | WR |
| | 7 | Victor Davis | Canada | 1:01.99 | NR |
| | 5 | Peter Evans | Australia | 1:02.97 | |
| 4 | 1 | Adrian Moorhouse | Great Britain | 1:03.25 | |
| 5 | 4 | John Moffet | United States | 1:03.29 | |
| 6 | 3 | Brett Stocks | Australia | 1:03.49 | |
| 7 | 6 | Gerald Mörken | West Germany | 1:03.95 | |
| 8 | 8 | Raffaele Avagnano | Italy | 1:04.11 | |