Swimming at the 2003 World Aquatics Championships – Men's 100 metre butterfly
# Swimming at the 2003 World Aquatics Championships – Men's 100 metre butterfly

The Men's 100 Butterfly event at the 10th FINA World Aquatics Championships swam 25–26 July 2003 in Barcelona, Spain. Preliminary and Semifinal heats swam July 25, with the prelims during the morning session and the semifinals in the evening session. The Final was held on July 26.

At the start of the event, the existing World (WR) and Championship (CR) records were both:

* WR: 51.81 swum by Michael Klim (Australia) on December 12, 1999 in Canberra, Australia.
* CR: 52.10 swum by Lars Frölander (Sweden) on July 26, 2001 in Fukuoka, Japan

## Results

### Final

| Place | Swimmer | Nation | Time | Notes |
| - | - | - | - | - |
| 1 | Ian Crocker | USA | 50.98 | WR |
| 2 | Michael Phelps | USA | 51.10 | |
| 3 | Andrii Serdinov | Ukraine | 51.59 | |
| 4 | Igor Marchenko | Russia | 51.95 | |
| 5 | Thomas Rupprath | Germany | 51.98 | |
| 6 | Takashi Yamamoto | Japan | 52.27 | |
| 7 | Franck Esposito | France | 52.68 | |
| 8 | Evgueni Korotychkine | Russia | 53.00 | |

### Semifinals

| Rank | Heat+Lane | Swimmer | Nation | Time | Notes |
| - | - | - | - | - | - |
| 1 | S2 L4 | Michael Phelps | USA | 51.47 | q, WR |
| 2 | S1 L6 | Andrii Serdinov | Ukraine | 51.76 | q, WR |
| 3 | S1 L4 | Ian Crocker | USA | 52.21 | q |
| 4 | S1 L5 | Thomas Rupprath | Germany | 52.37 | q |
| 5 | S1 L2 | Igor Marchenko | Russia | 52.44 | q |
| 6 | S2 L5 | Franck Esposito | France | 52.49 | q |
| 7 | S1 L8 | Evgueni Korotychkine | Russia | 52.55 | q |
| 7 | S2 L3 | Takashi Yamamoto | Japan | 52.55 | q |
| 9 | S1 L3 | Mike Mintenko | Canada | 52.57 | |
| 10 | S1 L1 | Joris Keizer | Netherlands | 52.64 | |
| 11 | S1 L7 | Adam Pine | Australia | 53.05 | |
| 12 | S2 L8 | Denis Sylantyev | Ukraine | 53.12 | |
| 13 | S2 L7 | Geoff Huegill | Australia | 53.13 | |
| 14 | S2 L2 | Mattia Nalesso | Italy | 53.16 | |
| 15 | S2 L1 | Ioan Gherghel | Romania | 53.18 | |
| 16 | S2 L6 | Johannes Dietrich | Germany | 53.76 | |

### Preliminaries

| Rank | Heat+Lane | Swimmer | Nation | Time | Notes |
| - | - | - | - | - | - |
| 1 | H15 L4 | Michael Phelps | United States | 52.27 | q |
| 2 | H15 L5 | Ian Crocker | United States | 52.35 | q |
| 3 | H14 L3 | Franck Esposito | France | 52.85 | q |
| 4 | H14 L4 | Thomas Rupprath | Germany | 52.91 | q |
| 4 | H14 L6 | Takashi Yamamoto | Japan | 52.91 | q |
| 6 | H15 L3 | Mike Mintenko | Canada | 52.92 | q |
| 7 | H12 L3 | Johannes Dietrich | Germany | 53.01 | q |
| 8 | H13 L4 | Andrii Serdinov | Ukraine | 53.06 | q |
| 9 | H14 L8 | Mattia Nalesso | Italy | 53.12 | q |
| 10 | H13 L5 | Igor Marchenko | Russia | 53.21 | q |
| 11 | H14 L5 | Geoff Huegill | Australia | 53.28 | q |
| 12 | H15 L2 | Adam Pine | Australia | 53.31 | q |
| 13 | H15 L8 | Ioan Gherghel | Romania | 53.42 | q |
| 14 | H15 L6 | Joris Keizer | Netherlands | 53.44 | q |
| 15 | H12 L5 | Denis Sylantyev | Ukraine | 53.45 | q |
| 16 | H15 L7 | Evgueni Korotychkine | Russia | 53.48 | q |
| 17 | H13 L6 | Pavel Lagoun | Belarus | 53.68 | |
| 18 | H13 L3 | Lars Frölander | Sweden | 53.74 | |
| 19 | H13 L7 | Corney Swanepoel | New Zealand | 53.95 | |
| 20 | H14 L7 | Josh Ilika | Mexico | 53.96 | |
| 20 | H14 L1 | Zsolt Gáspár | Hungary | 53.96 | |
| 22 | H12 L7 | Kaio Almeida | Brazil | 53.98 | |
| 23 | H12 L8 | Ryan Pini | Papua New Guinea | 54.05 | |
| 24 | H11 L5 | Tero Välimaa | Finland | 54.07 | |
| 25 | H10 L1 | Luis Rojas | Venezuela | 54.09 | |
| 25 | H15 L1 | Hao Jin | China | 54.09 | |
| 27 | H12 L6 | Theo Verster | South Africa | 54.16 | |
| 28 | H13 L2 | Jere Hård | Finland | 54.21 | |
| 29 | H10 L6 | Andrew Livingston | Puerto Rico | 54.48 | |
| 30 | H11 L6 | Camilo Becerra | Colombia | 54.56 | |
| 31 | H11 L3 | Ravil Nachaev | Uzbekistan | 54.64 | |
| 31 | H13 L1 | Rimvydas Salcius | Lithuania | 54.64 | |
| 33 | H11 L1 | Georgi Palazov | Bulgaria | 54.70 | |
| 34 | H12 L4 | Simão Morgado | Portugal | 54.81 | |
| 35 | H11 L7 | Lyndon Ferns | South Africa | 54.94 | |
| 36 | H10 L8 | Romāns Miloslavskis | Latvia | 55.12 | |
| 37 | H11 L4 | Erik Andersson | Sweden | 55.19 | |
| 37 | H11 L8 | Jeong Doo-Hee | South Korea | 55.19 | |
| 37 | H12 L2 | Gabriel Mangabeira | Brazil | 55.19 | |
| 40 | H10 L5 | Aleksandar Miladinovski | Macedonia | 55.23 | |
| 41 | H09 L2 | Petter Sjodal | Norway | 55.27 | |
| 42 | H09 L4 | Aghiles Slimani | Algeria | 55.40 | |
| 43 | H08 L4 | Pavel Suškov | Lithuania | 55.64 | |
| 44 | H09 L3 | Rustam Khudiyev | Kazakhstan | 55.66 | |
| 45 | H07 L4 | Nicholas Rees | Bahamas | 55.89 | |
| 46 | H10 2L | Philipp Gilgen | Switzerland | 55.90 | |
| 47 | H10 L7 | Zoran Lazarovski | Macedonia | 55.93 | |
| 48 | H10 L3 | Luis Monteiro | Portugal | 55.95 | |
| 49 | H10 L4 | David Kolozar | Hungary | 56.07 | |
| 50 | H09 L1 | Jae Hyon Joe | South Korea | 56.30 | |
| 51 | H08 L8 | Huazhang Zheng | China | 56.36 | |
| 52 | H08 L6 | Conrad Francis | Sri Lanka | 56.55 | |
| 53 | H09 L5 | Luc Decker | Luxembourg | 56.56 | |
| 54 | H09 L6 | Albert Subirats | Venezuela | 56.73 | |
| 55 | H08 L5 | Oleg Lyashko | Uzbekistan | 56.76 | |
| 56 | H09 L8 | Raouf Benabid | Algeria | 56.88 | |
| 57 | H09 L7 | Yu Lung Lubrey Lim | Malaysia | 56.95 | |
| 58 | H06 L5 | Lorenz Liechti | Switzerland | 57.04 | |
| 59 | H08 L3 | Wing Cheung Victor Wong | Macau | 57.28 | |
| 60 | H07 L2 | Nedim Nišić | Bosnia and Herzegovina | 57.39 | |
| 61 | H08 L1 | William Muriel | Ecuador | 57.52 | |
| 62 | H07 L7 | Ignacio Sanchez Leon | Peru | 57.69 | |
| 63 | H08 L2 | Shui Ki Szeto | Hong Kong | 57.81 | |
| 64 | H06 L4 | Jorge Arturo Arce | Costa Rica | 57.87 | |
| 65 | H07 L8 | Gunther Streit | Namibia | 57.93 | |
| 66 | H07 L5 | James Walsh | Philippines | 58.04 | |
| 67 | H04 L7 | Khaly Ciss | Senegal | 58.62 | |
| 68 | H06 L2 | Tuck Kar Wong | Malaysia | 58.66 | |
| 69 | H05 L4 | Davy Bisslik | Aruba | 58.67 | |
| 70 | H06 L7 | Miguel Navarro | Bolivia | 58.71 | |
| 70 | H07 L3 | Sergio Cabrera | Paraguay | 58.71 | |
| 72 | H08 L7 | David Cartin | Costa Rica | 58.79 | |
| 73 | H07 L6 | Stavros Michaelides | Cyprus | 58.80 | |
| 74 | H06 L1 | Jean Paul Adam | Seychelles | 58.85 | |
| 75 | H05 L3 | Yann Lausan | Tahiti | 58.91 | |
| 76 | H06 L3 | Gordon Touw Ngie Tjouw | Suriname | 59.05 | |
| 77 | H05 L2 | Roy Barahona | Honduras | 59.09 | |
| 78 | H05 L5 | Jewel Md. Jewel Ahmed | Bangladesh | 59.22 | |
| 79 | H05 L7 | Cliff Gittens | Barbados | 59.35 | |
| 80 | H06 L8 | Zurab Khomasuridze | Georgia | 59.56 | |
| 81 | H07 L1 | Rafael de Leon Alfaro | Guatemala | 59.81 | |
| 82 | H05 L8 | Malick Fall | Senegal | 59.90 | |
| 83 | H04 L5 | Chad Miller | Fiji | 59.93 | |
| 84 | H04 L8 | Bertrand Bristol | Seychelles | 1:00.30 | |
| 85 | H02 L4 | Fernando Medrano | Nicaragua | 1:00.80 | |
| 86 | H02 L2 | Musa Bakare | Nigeria | 1:00.87 | |
| 87 | H04 L4 | Abed Rahman Kaaki | Lebanon | 1:01.08 | |
| 88 | H03 L2 | Obied Ahmed Al Jassimi | United Arab Emirates | 1:01.16 | |
| 89 | H03 L5 | Dean Palacios | Northern Mariana Islands | 1:01.19 | |
| 90 | H04 L3 | Joao Matias | Angola | 1:01.37 | |
| 91 | H04 L6 | Marc Dansou | Benin | 1:01.66 | |
| 92 | H01 L1 | Aung Kyaw Moe | Myanmar | 1:01.67 | |
| 93 | H05 L1 | Babak Farhoudi | Iran | 1:01.73 | |
| 94 | H02 L3 | Joao Aguiar | Angola | 1:01.89 | |
| 95 | H03 L6 | Omar Núñez | Nicaragua | 1:02.15 | |
| 96 | H04 L2 | Benjamin Wells | Papua New Guinea | 1:02.31 | |
| 97 | H03 L7 | Ammar Musaed Al Tamimi | United Arab Emirates | 1:02.41 | |
| 98 | H01 L4 | Ilidio Matusse | Mozambique | 1:02.95 | |
| 98 | H03 L4 | Raad Awisat | Palestine | 1:02.95 | |
| 100 | H02 L8 | Kabir Walia | Kenya | 1:03.18 | |
| 101 | H02 L7 | Rony Bakale | Republic of the Congo | 1:03.61 | |
| 102 | H03 L8 | Zaid Saeed | Iraq | 1:04.42 | |
| 103 | H05 L6 | Gustavo Adolfo Martinez | Honduras | 1:05.57 | |
| 104 | H01 L7 | Maximilien J. Doualla Frederic | Cameroon | 1:06.14 | |
| 105 | H02 L5 | Daniel Kang | Guam | 1:06.30 | |
| 106 | H01 L5 | Kin-Vincent Duenas | Guam | 1:06.46 | |
| 107 | H02 L1 | Neils Agius | Malta | 1:07.19 | |
| 108 | H01 L6 | Muzeya Muzyamba | Zambia | 1:08.82 | |
| 109 | H01 L2 | Chisela Kanchela | Zambia | 1:12.62 | |
| 110 | H01 L8 | Hassan Mubah | Maldives | 1:14.43 | |
| - | H14 L2 | Ryo Takayasu | Japan | DQ | |
| - | - | Frédérick Bousquet | France | DNS | |
| - | - | Milorad Čavić | FR Yugoslavia | DNS | |
| - | - | Pablo Martín Abal | Argentina | DNS | |
| - | - | Ronald Cowen | Bermuda | DNS | |
| - | - | Gregory Arkhurst | Ivory Coast | DNS | |
| - | - | Landry Degnifo Enokorin | Ivory Coast | DNS | |
| - | - | Yan Lin Aung | Myanmar | DNS | |
| - | - | Sean Chow | Fiji | DNS | |
| - | - | Clark Randrianandraina | Madagascar | DNS | |
