Swimming at the 2003 World Aquatics Championships – Women's 400 metre freestyle
# Swimming at the 2003 World Aquatics Championships – Women's 400 metre freestyle

The Women's 400m Freestyle event at the 10th FINA World Aquatics Championships swam on 20 July 2003 in Barcelona, Spain. Preliminary heats swam during the day's morning session, with the top-8 finishers advancing to swim again in the Final during the evening session.

Prior to the event, the World (WR) and Championship (CR) records were:

* WR: 4:03.85 swum by Janet Evans (USA) on September 22, 1988, in Seoul, South Korea
* CR: 4:06.28 swum by Tracey Wickham (Australia) on August 24, 1978, in Berlin, Germany

## Results

### Final

| Place | Swimmer | Nation | Time |
| - | - | - | - |
| 1 | Hannah Stockbauer | Germany | 4:06.75 |
| 2 | Éva Risztov | Hungary | 4:07.24 |
| 3 | Diana Munz | USA | 4:07.67 |
| 4 | Elka Graham | Australia | 4:08.60 |
| 5 | Brittany Reimer | Canada | 4:09.34 |
| 6 | Lindsay Benko | USA | 4:09.82 |
| 7 | Simona Păduraru | Romania | 4:13.62 |
| 8 | Hua Chen | China | 4:13.75 |

### Preliminaries

| Rank | Heat+Lane | Swimmer | Nation | Time | Notes |
| - | - | - | - | - | - |
| 1 | H5 L5 | Hannah Stockbauer | Germany | 4:09.78 | q |
| 2 | H5 L4 | Diana Munz | United States | 4:09.90 | q |
| 3 | H6 L4 | Éva Risztov | Hungary | 4:10.41 | q |
| 4 | H5 L6 | Elka Graham | Australia | 4:10.58 | q |
| 5 | H6 L5 | Hua Chen | China | 4:11.07 | q |
| 5 | H6 L3 | Simona Păduraru | Romania | 4:11.07 | q |
| 7 | H4 L5 | Lindsay Benko | United States | 4:11.20 | q |
| 8 | H4 L6 | Brittany Reimer | Canada | 4:11.55 | q |
| 9 | H4 L4 | Sashiko Yamada | Japan | 4:12.29 | |
| 10 | H5 L3 | Jana Henke | Germany | 4:12.32 | |
| 11 | H6 L2 | Zoi Dimoschaki | Greece | 4:12.48 | |
| 12 | H6 L6 | Rebecca Cooke | Great Britain | 4:12.51 | |
| 13 | H4 L3 | Laure Manaudou | France | 4:12.66 | |
| 14 | H5 L7 | Ai Shibata | Japan | 4:13.78 | |
| 15 | H6 L7 | Regina Sytch | Russia | 4:13.79 | |
| 16 | H5 L2 | Erika Villaécija | Spain | 4:14.10 | |
| 17 | H4 L2 | Linda Mackenzie | Australia | 4:14.36 | |
| 18 | H5 L1 | Melissa Caballero | Spain | 4:14.47 | |
| 19 | H3 L4 | Mariana Brochado | Brazil | 4:15.29 | |
| 20 | H3 L5 | Chantal Strasser | Switzerland | 4:15.44 | |
| 21 | H6 L1 | Daria Parshina | Russia | 4:15.63 | |
| 22 | H4 L8 | Anja Čarman | Slovenia | 4:16.70 | |
| 23 | H3 L3 | Marianna Lymperta | Greece | 4:17.42 | |
| 24 | H3 L2 | Vesna Stojanvoska | Macedonia | 4:17.52 | |
| 25 | H5 L8 | Jingzhi Tang | China | 4:17.77 | |
| 26 | H6 L8 | Melissa Corfe | South Africa | 4:18.41 | |
| 27 | H4 L7 | Monique Ferreira | Brazil | 4:18.90 | |
| 28 | H4 L1 | Jana Pechanová | Czech Republic | 4:18.93 | |
| 29 | H3 L8 | Alison Fitch | New Zealand | 4:20.38 | |
| 30 | H3 L6 | Olga Beresneva | Ukraine | 4:23.03 | |
| 31 | H3 L1 | Pilin Tachakittiraran | Thailand | 4:23.80 | |
| 32 | H1 L5 | Maria Albert | Estonia | 4:24.08 | |
| 33 | H2 L5 | Kristel Köbrich | Chile | 4:24.53 | |
| 34 | H3 L7 | Marta Ferreira | Portugal | 4:25.38 | |
| 35 | H2 L3 | Golda Marcus | El Salvador | 4:28.03 | |
| 36 | H2 L1 | Johana Rodriguez | Costa Rica | 4:36.43 | |
| 37 | H2 L2 | Magdalena Sutanto | Indonesia | 4:37.45 | |
| 38 | H2 L4 | Andrea De León | Uruguay | 4:39.07 | |
| 39 | H2 L7 | Roberta Callus | Malta | 4:42.71 | |
| 40 | H2 L6 | Sivranjani Vaidyanathan | India | 4:42.89 | |
| 41 | H1 L4 | Man Wai Fong | Macau | 4:50.53 | |
| - | - | Corise Nyenimigabo | Burundi | DNS | |
