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

The final of the men's 100 metre butterfly event at the 1984 Summer Olympics was held in the McDonald's Olympic Swim Stadium in Los Angeles, California, on July 30, 1984.

## Records

Prior to this competition, the existing world and Olympic records were as follows.
| World record | Pablo Morales (USA) | 53.38 | Indianapolis, United States | 26 June 1984 |
| Olympic record | Mark Spitz (USA) | 54.27 | Munich, West Germany | 31 August 1972 |
The following records were established during the competition:
| Date | Round | Name | Nation | Time | Record |
| 30 July | Heat 7 | Pablo Morales | United States | 53.78 | OR |
| 30 July | Final A | Michael Gross | West Germany | 53.08 | 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 | Pablo Morales | United States | 53.78 | Q, OR |
| 2 | 6 | 4 | Michael Gross | West Germany | 54.02 | Q, ER |
| 3 | 2 | 4 | Rafael Vidal | Venezuela | 54.33 | Q, NR |
| 4 | 4 | 5 | Andy Jameson | Great Britain | 54.59 | Q, NR |
| 5 | 5 | 5 | Bengt Baron | Sweden | 54.67 | Q |
| 6 | 1 | 5 | Glenn Buchanan | Australia | 54.86 | Q, OC |
| 7 | 7 | 6 | Anthony Mosse | New Zealand | 55.19 | Q, NR |
| 8 | 3 | 5 | Andreas Behrend | West Germany | 55.22 | Q |
| 9 | 4 | 4 | Tom Ponting | Canada | 55.23 | q |
| 10 | 1 | 3 | Dano Halsall | Switzerland | 55.35 | q |
| 11 | 5 | 4 | Matt Gribble | United States | 55.39 | q, WD |
| 12 | 3 | 6 | Kristofer Stivenson | Greece | 55.46 | q, NR |
| 12 | 5 | 3 | Cees Vervoorn | Netherlands | 55.46 | q |
| 14 | 1 | 4 | David López-Zubero | Spain | 55.66 | q |
| 15 | 2 | 5 | Fabrizio Rampazzo | Italy | 55.70 | q |
| 15 | 7 | 3 | Mark Stockwell | Australia | 55.70 | q, WD |
| 17 | 6 | 5 | Søren Østberg | Denmark | 55.73 | q |
| 18 | 6 | 3 | Théophile David | Switzerland | 55.81 | q |
| 19 | 7 | 5 | David Churchill | Canada | 55.84 | |
| 20 | 2 | 6 | Harri Garmendia | Spain | 55.97 | |
| 21 | 3 | 2 | Anthony Nesty | Suriname | 56.15 | NR |
| 22 | 4 | 6 | Taihei Saka | Japan | 56.40 | |
| 23 | 6 | 6 | Ian Collins | Great Britain | 56.41 | |
| 24 | 5 | 6 | Shudo Kawawa | Japan | 56.52 | |
| 25 | 1 | 6 | İhsan Sabri Özün | Turkey | 56.55 | NR |
| 25 | 3 | 2 | Gérard de Kort | Netherlands | 56.55 | |
| 27 | 6 | 2 | Zheng Jian | China | 56.58 | |
| 28 | 4 | 3 | Ang Peng Siong | Singapore | 56.61 | NR |
| 29 | 3 | 4 | Filiberto Colon | Puerto Rico | 56.66 | |
| 30 | 2 | 3 | Hrvoje Barić | Yugoslavia | 56.70 | |
| 31 | 7 | 7 | Luis Juncos | Argentina | 56.86 | NR |
| 32 | 7 | 2 | Carlos Scanavino | Uruguay | 57.46 | |
| 33 | 6 | 7 | Carlos Romo | Mexico | 57.61 | |
| 34 | 4 | 2 | Allan Marsh | Jamaica | 57.69 | |
| 35 | 5 | 7 | Ahmed Said | Egypt | 57.71 | |
| 36 | 5 | 2 | Kemal Sadri Özün | Turkey | 57.75 | |
| 37 | 4 | 7 | João Santos | Portugal | 58.17 | |
| 38 | 1 | 2 | Tsang Yi Ming | Hong Kong | 58.25 | |
| 39 | 2 | 2 | Sean Nottage | Bahamas | 58.73 | |
| 40 | 3 | 7 | Bang Jun-young | South Korea | 58.91 | |
| 41 | 2 | 7 | Ahmed Eid | Egypt | 58.95 | |
| 42 | 1 | 7 | Deryck Marks | Jamaica | 1:00.57 | |
| 43 | 7 | 1 | Ingi Jónsson | Iceland | 1:00.68 | |
| 44 | 3 | 1 | Faisal Marzouk | Kuwait | 1:02.00 | |
| 45 | 6 | 1 | Roberto Granados | Guatemala | 1:02.32 | |
| 46 | 5 | 8 | Juan Miranda Trejo | El Salvador | 1:04.33 | |
| 47 | 4 | 1 | Ibrahim El-Baba | Lebanon | 1:04.48 | |
| 48 | 1 | 1 | Adel Al-Ghaith | Kuwait | 1:04.62 | |
| 49 | 5 | 1 | Warren Sorby | Fiji | 1:05.53 | |
| 50 | 4 | 8 | Salvador Corelo | Honduras | 1:05.91 | |
| 51 | 7 | 8 | Trevor Ncala | Swaziland | 1:06.94 | |
| 52 | 2 | 1 | Samuela Tupou | Fiji | 1:07.75 | |
| 53 | 6 | 8 | Esa Fadel | Bahrain | 1:13.27 | |

### Finals
#### Final B

| Rank | Lane | Name | Nationality | Time |
| 9 | 4 | Tom Ponting | Canada | 55.31 |
| 10 | 8 | Théophile David | Switzerland | 55.40 |
| 11 | 5 | Dano Halsall | Switzerland | 55.51 |
| 12 | 3 | David López-Zubero | Spain | 55.61 |
| 12 | 6 | Kristofer Stivenson | Greece | 55.61 |
| 14 | 2 | Cees Vervoorn | Netherlands | 55.75 |
| 15 | 1 | Søren Østberg | Denmark | 56.04 |
| | 7 | Fabrizio Rampazzo | Italy | DNS |

#### Final A

| Rank | Lane | Name | Nationality | Time | Notes |
| | 5 | Michael Gross | West Germany | 53.08 | WR |
| | 4 | Pablo Morales | United States | 53.23 | AM |
| | 7 | Glenn Buchanan | Australia | 53.85 | OC |
| 4 | 3 | Rafael Vidal | Venezuela | 54.27 | NR |
| 5 | 6 | Andy Jameson | Great Britain | 54.28 | NR |
| 6 | 1 | Anthony Mosse | New Zealand | 54.93 | NR |
| 7 | 8 | Andreas Behrend | West Germany | 54.95 | |
| 8 | 2 | Bengt Baron | Sweden | 55.14 | |