# Swimming at the 2019 World Aquatics Championships – Men's 100 metre butterfly

The Men's 100 metre butterfly competition at the 2019 World Championships was held on 26 and 27 July 2019. The defending champion Caeleb Dressel broke Michael Phelps' ten-year-old record by 0.32 second in the semi-final, setting a new world-record time of 49.50 seconds. Dressel won the final held the following day, defending his title.

## Records

Prior to the competition, the existing world and championship records were as follows.
| World record | Michael Phelps (USA) | 49.82 | Rome, Italy | 1 August 2009 |
| Competition record | Michael Phelps (USA) | 49.82 | Rome, Italy | 1 August 2009 |
The following new records were set during this competition.
| Date | Event | Name | Nationality | Time | Record |
| 26 July | Semifinal | Caeleb Dressel | United States | 49.50 | WR |

## Results
### Heats

The heats were held on 26 July at 10:00.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 9 | 4 | Caeleb Dressel | United States | 50.28 | Q |
| 2 | 7 | 2 | Kristóf Milák | Hungary | 51.42 | Q |
| 3 | 9 | 3 | Andrey Minakov | Russia | 51.54 | Q |
| 4 | 7 | 4 | Chad le Clos | South Africa | 51.58 | Q |
| 5 | 9 | 5 | Mehdy Metella | France | 51.65 | Q |
| 6 | 9 | 6 | Vinicius Lanza | Brazil | 51.83 | Q |
| 7 | 9 | 7 | László Cseh | Hungary | 51.88 | Q |
| 8 | 8 | 2 | Matthew Temple | Australia | 51.89 | Q |
| 9 | 8 | 5 | Jack Conger | United States | 51.96 | Q |
| 10 | 7 | 3 | Marius Kusch | Germany | 52.05 | Q |
| 11 | 8 | 3 | James Guy | Great Britain | 52.06 | Q |
| 12 | 8 | 6 | Naoki Mizunuma | Japan | 52.23 | Q |
| 13 | 7 | 1 | Tomer Frankel | Israel | 52.36 | Q |
| 14 | 7 | 6 | Li Zhuhao | China | 52.44 | Q |
| 14 | 9 | 1 | Yauhen Tsurkin | Belarus | 52.44 | Q |
| 14 | 9 | 2 | David Morgan | Australia | 52.44 | Q |
| 17 | 7 | 8 | Adilbek Mussin | Kazakhstan | 52.46 | |
| 18 | 8 | 9 | Deividas Margevičius | Lithuania | 52.55 | NR |
| 19 | 7 | 7 | Federico Burdisso | Italy | 52.65 | |
| 20 | 8 | 7 | Konrad Czerniak | Poland | 52.77 | |
| 21 | 6 | 2 | Ümitcan Gureş | Turkey | 52.86 | |
| 22 | 9 | 8 | Mathys Goosen | Netherlands | 52.87 | |
| 23 | 6 | 4 | Kregor Zirk | Estonia | 52.92 | |
| 24 | 7 | 5 | Joseph Schooling | Singapore | 52.93 | |
| 24 | 8 | 0 | Josiah Binnema | Canada | 52.93 | |
| 26 | 8 | 4 | Piero Codia | Italy | 53.09 | |
| 27 | 8 | 8 | Daniel Martin | Romania | 53.15 | |
| 28 | 6 | 1 | Denys Kesil | Ukraine | 53.39 | |
| 29 | 7 | 9 | Andreas Vazaios | Greece | 53.41 | |
| 30 | 8 | 1 | Ryan Coetzee | South Africa | 53.46 | |
| 31 | 5 | 6 | Mihajlo Čeprkalo | Bosnia and Herzegovina | 53.52 | NR |
| 32 | 5 | 4 | Chu Chen-ping | Chinese Taipei | 53.58 | |
| 33 | 6 | 6 | Riku Pöytäkivi | Finland | 53.62 | |
| 34 | 6 | 3 | Yun Seok-hwan | South Korea | 53.64 | |
| 35 | 6 | 5 | Simon Sjödin | Sweden | 53.70 | |
| 36 | 5 | 5 | Bradlee Ashby | New Zealand | 53.73 | |
| 37 | 6 | 9 | Benjamin Hockin | Paraguay | 53.78 | |
| 38 | 5 | 3 | Chan Jie | Malaysia | 53.85 | |
| 39 | 6 | 8 | Roberto Strelkov | Argentina | 54.11 | |
| 40 | 5 | 7 | Yusuf Tibazi | Morocco | 54.21 | |
| 41 | 6 | 0 | Sajan Prakash | India | 54.30 | |
| 42 | 5 | 8 | Nicholas Lim | Hong Kong | 54.36 | |
| 43 | 5 | 0 | Navaphat Wongcharoen | Thailand | 54.38 | |
| 44 | 6 | 7 | Glenn Victor Sutanto | Indonesia | 54.57 | |
| 45 | 1 | 5 | Abbas Qali | Kuwait | 54.67 | |
| 46 | 4 | 4 | Cadell Lyons | Trinidad and Tobago | 54.79 | |
| 47 | 5 | 2 | Steven Aimable | Senegal | 54.94 | NR |
| 47 | 5 | 9 | Abeiku Jackson | Ghana | 54.94 | |
| 49 | 5 | 1 | Ralph Goveia | Zambia | 55.14 | |
| 50 | 4 | 6 | Ayman Kelzi | Syria | 55.15 | NR |
| 51 | 4 | 3 | Alireza Yavari | Iran | 55.63 | |
| 52 | 4 | 5 | Keanan Dols | Jamaica | 55.66 | |
| 53 | 4 | 2 | Teimuraz Kobakhidze | Georgia | 56.03 | |
| 54 | 4 | 1 | Bryan Alvaréz | Costa Rica | 56.04 | |
| 55 | 4 | 0 | Jayhan Odlum-Smith | Saint Lucia | 56.31 | |
| 56 | 2 | 5 | Artur Barseghyan | Armenia | 56.52 | |
| 57 | 4 | 7 | Seggio Bernardina | Curaçao | 56.54 | |
| 58 | 3 | 5 | Yousif Bu Arish | Saudi Arabia | 56.58 | |
| 59 | 4 | 8 | Yacob Al-Khulaifi | Qatar | 56.62 | |
| 60 | 3 | 4 | Rami Anis | FINA Independent Athletes | 57.26 | |
| 61 | 3 | 3 | Jesse Washington | Bermuda | 57.29 | |
| 62 | 3 | 8 | Salvador Gordo | Angola | 57.32 | |
| 63 | 1 | 3 | Ifeakachuku Nmor | Nigeria | 57.65 | |
| 64 | 3 | 7 | Simon Bachmann | Seychelles | 58.06 | |
| 65 | 3 | 1 | Bernat Lomero | Andorra | 58.12 | |
| 66 | 4 | 9 | Fernando Ponce | Guatemala | 58.26 | |
| 67 | 1 | 4 | Abdulla Ahmed | Bahrain | 58.44 | NR |
| 68 | 3 | 0 | Collins Saliboko | Tanzania | 58.82 | |
| 69 | 3 | 6 | Davidson Vincent | Haiti | 58.91 | |
| 70 | 3 | 2 | Mathieu Marquet | Mauritius | 1:00.03 | |
| 71 | 2 | 1 | Daniel Christian | Eritrea | 1:00.77 | |
| 72 | 2 | 3 | Ousmane Touré | Mali | 1:00.81 | |
| 73 | 3 | 9 | Emilien Puyo | Monaco | 1:01.12 | |
| 74 | 2 | 2 | Lim Keouodom | Cambodia | 1:01.17 | |
| 75 | 2 | 8 | Simanga Dlamini | Eswatini | 1:02.39 | |
| 76 | 2 | 4 | Belly-Cresus Ganira | Burundi | 1:03.34 | |
| 77 | 2 | 7 | Achala Gekabel | Ethiopia | 1:06.40 | |
| | 2 | 6 | Irvin Hoost | Suriname | DSQ | DSQ |
| | 7 | 0 | Viktor Bromer | Denmark | DNS | DNS |
| | 9 | 0 | Tomoe Zenimoto Hvas | Norway | DNS | DNS |
| | 9 | 9 | Antani Ivanov | Bulgaria | DNS | DNS |

### Semifinals

The semifinals were held on 26 July at 20:10.

#### Semifinal 1

| Rank | Lane | Name | Nationality | Time | Notes |
| 1 | 4 | Kristóf Milák | Hungary | 50.95 | Q |
| 2 | 5 | Chad le Clos | South Africa | 51.40 | Q |
| 3 | 2 | Marius Kusch | Germany | 51.50 | Q |
| 4 | 6 | Matthew Temple | Australia | 51.70 | Q |
| 5 | 7 | Naoki Mizunuma | Japan | 51.71 | |
| 6 | 3 | Vinicius Lanza | Brazil | 51.92 | |
| 7 | 1 | Li Zhuhao | China | 52.00 | |
| 8 | 8 | David Morgan | Australia | 52.20 | |

#### Semifinal 2

| Rank | Lane | Name | Nationality | Time | Notes |
| 1 | 4 | Caeleb Dressel | United States | 49.50 | Q, WR |
| 2 | 5 | Andrey Minakov | Russia | 50.94 | Q, NR |
| 3 | 3 | Mehdy Metella | France | 51.62 | Q |
| 4 | 7 | James Guy | Great Britain | 51.69 | Q |
| 5 | 6 | László Cseh | Hungary | 51.86 | |
| 6 | 2 | Jack Conger | United States | 51.91 | |
| 7 | 1 | Tomer Frankel | Israel | 52.15 | NR |
| 8 | 8 | Yauhen Tsurkin | Belarus | 52.55 | |

### Final

The final was started on 27 July at 20:43.
| Rank | Lane | Name | Nationality | Time | Notes |
| | 4 | Caeleb Dressel | United States | 49.66 | |
| | 5 | Andrey Minakov | Russia | 50.83 | NR |
| | 6 | Chad le Clos | South Africa | 51.16 | |
| 4 | 3 | Kristóf Milák | Hungary | 51.26 | |
| 5 | 7 | Mehdy Metella | France | 51.38 | |
| 6 | 8 | Matthew Temple | Australia | 51.51 | |
| 7 | 1 | James Guy | Great Britain | 51.62 | |
| 8 | 2 | Marius Kusch | Germany | 51.66 | |