# Swimming at the 2009 World Aquatics Championships – Women's 100 metre freestyle

The heats for the women's 100 m freestyle race at the 2009 World Championships took place on the morning of 30 July, with the final in the evening session of 31 July at the Foro Italico in Rome, Italy.

## Records

Prior to this competition, the existing world and competition records were as follows:
| World record | Britta Steffen (GER) | 52.56 | Berlin, Germany | 27 June 2009 |
| Championship record | Natalie Coughlin (USA) | 53.40 | Melbourne, Australia | 29 March 2007 |
| Championship record | Libby Lenton (AUS) | 53.40 | Melbourne, Australia | 30 March 2007 |
The following records were established during the competition:
| Date | Round | Name | Nationality | Time | Record |
| 26 July | Heat 4* | Francesca Halsall | Great Britain | 53.02 | CR |
| 26 July | Final* | Britta Steffen | Germany | 52.22 | WR |
| 31 July | Final | Britta Steffen | Germany | 52.07 | WR |
* Split from the women's 4 × 100 m freestyle relay

## Results
### Heats

| Rank | Name | Nationality | Time | Heat | Lane | Notes |
| 1 | Amanda Weir | United States | 53.20 | 16 | 6 | AM |
| 2 | Libby Trickett | Australia | 53.49 | 16 | 4 | |
| 3 | Ranomi Kromowidjojo | Netherlands | 53.61 | 17 | 6 | |
| 4 | Britta Steffen | Germany | 53.62 | 17 | 4 | |
| 5 | Dana Vollmer | United States | 53.69 | 15 | 3 | |
| 6 | Jeanette Ottesen | Denmark | 53.79 | 15 | 6 | NR |
| 7 | Malia Metella | France | 53.91 | 17 | 5 | |
| 7 | Francesca Halsall | Great Britain | 53.91 | 17 | 3 | |
| 9 | Hanna-Maria Seppälä | Finland | 53.94 | 15 | 5 | |
| 9 | Evelyn Verrasztó | Hungary | 53.94 | 16 | 3 | NR |
| 11 | Daniela Schreiber | Germany | 54.08 | 16 | 7 | |
| 12 | Li Zhesi | China | 54.10 | 15 | 7 | |
| 12 | Hayley Palmer | New Zealand | 54.10 | 16 | 1 | NR |
| 14 | Victoria Poon | Canada | 54.27 | 15 | 1 | |
| 15 | Aleksandra Gerasimenya | Belarus | 54.52 | 17 | 7 | |
| 16 | Marieke Guehrer | Australia | 54.60 | 16 | 2 | |
| 17 | Anastasia Aksenova | Russia | 54.70 | 15 | 8 | NR |
| 18 | Josefin Lillhage | Sweden | 54.87 | 17 | 2 | |
| 19 | Arlene Semeco | Venezuela | 54.92 | 14 | 1 | SA |
| 19 | Dar'ya Stepanyuk | Ukraine | 54.92 | 16 | 9 | NR |
| 21 | Arianna Vanderpool-Wallace | Bahamas | 54.96 | 14 | 6 | NR |
| 22 | Tatiana Lemos | Brazil | 55.02 | 16 | 8 | |
| 23 | Heather MacLean | Canada | 55.44 | 17 | 1 | |
| 24 | Gabriella Fagundez | Sweden | 55.45 | 17 | 8 | |
| 24 | Miroslava Najdanovski | Serbia | 55.45 | 17 | 0 | |
| 26 | Birgit Koschischek | Austria | 55.76 | 15 | 9 | |
| 27 | Ragnheidur Ragnarsdottir | Iceland | 55.78 | 14 | 7 | |
| 28 | Katherine Wyld | Great Britain | 55.83 | 14 | 3 | |
| 29 | Lee Jae Young | South Korea | 55.86 | 13 | 6 | |
| 30 | Haruka Ueda | Japan | 55.91 | 16 | 0 | |
| 31 | Katarina Filova | Slovakia | 56.00 | 13 | 8 | |
| 32 | Vanessa García | Puerto Rico | 56.01 | 11 | 3 | |
| 33 | Liliana Ibanez | Mexico | 56.04 | 13 | 7 | NR |
| 33 | Sviatlana Khakhlova | Belarus | 56.04 | 17 | 9 | |
| 35 | Heysi Villareal | Cuba | 56.12 | 10 | 6 | |
| 35 | Nina Rangelova | Bulgaria | 56.12 | 13 | 9 | |
| 37 | Yayoi Matsumoto | Japan | 56.20 | 14 | 4 | |
| 37 | Katarzyna Wilk | Poland | 56.20 | 15 | 0 | |
| 39 | Anna Stylianou | Cyprus | 56.29 | 13 | 1 | |
| 39 | Quah Ting Wen | Singapore | 56.29 | 14 | 2 | |
| 41 | Clare Dawson | Ireland | 56.32 | 12 | 6 | NR |
| 42 | Jolien Sysmans | Belgium | 56.33 | 14 | 8 | |
| 43 | Petra Klosova | Czech Republic | 56.34 | 13 | 3 | |
| 44 | Natthanan Junkrajang | Thailand | 56.42 | 13 | 2 | |
| 45 | Henriette Brekke | Norway | 56.47 | 12 | 4 | |
| 46 | Cecilie Johannessen | Norway | 56.50 | 11 | 5 | |
| 47 | Katarina Listopadova | Slovakia | 56.54 | 12 | 2 | |
| 48 | Nicole Horn | Zimbabwe | 56.57 | 12 | 9 | |
| 49 | Eszter Dara | Hungary | 56.65 | 14 | 0 | |
| 50 | Nadia Colovini | Argentina | 56.66 | 14 | 5 | |
| 51 | Nina Van Koeckhoven | Belgium | 56.69 | 13 | 4 | |
| 51 | Nina Sovinek | Slovenia | 56.69 | 14 | 9 | |
| 53 | Loren Yamile Bahamonde | Ecuador | 56.73 | 12 | 8 | |
| 54 | Juanita Barreto Barreto | Colombia | 56.75 | 10 | 3 | |
| 55 | Nina Drolc | Slovenia | 56.76 | 11 | 4 | |
| 56 | Elina Partoka | Estonia | 56.77 | 9 | 8 | |
| 57 | Verena Klocker | Austria | 56.79 | 12 | 5 | |
| 58 | Emilia Pikkarainen | Finland | 56.94 | 13 | 0 | |
| 59 | Amanda Lim | Singapore | 56.95 | 13 | 5 | |
| 60 | Fiona Doyle | Ireland | 56.96 | 12 | 3 | |
| 61 | Kiera Aitken | Bermuda | 56.99 | 10 | 5 | NR |
| 62 | Rugile Mileisyte | Lithuania | 57.30 | 11 | 1 | |
| 63 | Christine Mailliet | Luxembourg | 57.35 | 11 | 2 | |
| 64 | Sherry Tsai | Hong Kong | 57.53 | 12 | 0 | |
| 65 | Pamela Benitez | El Salvador | 57.54 | 11 | 9 | |
| 66 | Annika Saarnak | Estonia | 57.58 | 11 | 8 | |
| 67 | Hang Yu Sze | Hong Kong | 57.61 | 10 | 0 | |
| 68 | Ximena Vilar | Venezuela | 57.66 | 10 | 9 | |
| 69 | Natasha Moodie | Jamaica | 57.71 | 11 | 7 | |
| 70 | Nicole Marmol | Ecuador | 57.93 | 11 | 6 | |
| 71 | Anna-Liza Mopio-Jane | Papua New Guinea | 57.97 | 9 | 6 | NR |
| 72 | Coral del Mar Lopez Rosario | Puerto Rico | 57.98 | 9 | 4 | |
| 73 | Kimberley Eeson | Zimbabwe | 58.06 | 8 | 5 | |
| 74 | Sharntelle McLean | Trinidad and Tobago | 58.31 | 10 | 1 | |
| 75 | Teisha Lightbourne | Bahamas | 58.47 | 8 | 2 | |
| 76 | Erika Stewart | Colombia | 58.48 | 10 | 7 | |
| 77 | Fella Bennaceur | Algeria | 58.49 | 11 | 0 | |
| 78 | Kristina Tchernychev | Israel | 58.53 | 1 | 1 | |
| 79 | Chinyere Pigot | Suriname | 58.57 | 9 | 7 | NR |
| 80 | Leung Chii Lin | Malaysia | 58.64 | 10 | 8 | |
| 81 | Grite Apanaviciute | Lithuania | 58.70 | 12 | 1 | |
| 82 | Marie Laura Meza | Costa Rica | 58.88 | 8 | 4 | |
| 83 | Maida Turnadzic | Bosnia and Herzegovina | 58.91 | 12 | 7 | |
| 84 | Marianela Quesada | Costa Rica | 59.25 | 7 | 4 | |
| 85 | Ashley Bransford | Aruba | 59.27 | 9 | 1 | |
| 86 | Karen Milenka Torrez Guzman | Bolivia | 59.42 | 8 | 3 | |
| 87 | Farida Osman | Egypt | 59.45 | 10 | 2 | |
| 88 | Amina Meho | Lebanon | 59.60 | 9 | 3 | |
| 89 | Clelia Tini | San Marino | 59.62 | 8 | 1 | |
| 90 | Shaila Millum Garðarnar | Faroe Islands | 59.63 | 8 | 8 | NR |
| 91 | Miriam Hatamleh | Jordan | 59.84 | 7 | 6 | |
| 92 | Nishani Cicilson | Suriname | 59.94 | 6 | 8 | |
| 93 | Sara Abdullahu | Albania | 1:00.14 | 7 | 1 | NR |
| 94 | Raffaella Rodoni Palma | Chile | 1:00.31 | 9 | 0 | |
| 95 | Baean Jouma | Syria | 1:00.47 | 7 | 5 | |
| 95 | Chittaranjan Shubha | India | 1:00.47 | 7 | 7 | |
| 97 | Daniela Miyahara Coello | Peru | 1:00.63 | 7 | 3 | |
| 97 | Sharon Paola Fajardo Sierra | Honduras | 1:00.63 | 8 | 6 | |
| 99 | Noelyn Faussane | French Polynesia | 1:00.70 | 6 | 4 | |
| 100 | Talasha Prabhu | India | 1:00.73 | 7 | 9 | |
| 101 | Jonay Briedenhann | Namibia | 1:00.75 | 6 | 2 | |
| 102 | Christine Briedenhann | Namibia | 1:00.78 | 6 | 3 | |
| 103 | Natalya Filina | Azerbaijan | 1:00.84 | 7 | 8 | |
| 104 | Melinda Sue Micallef | Malta | 1:00.99 | 7 | 2 | |
| 104 | Razan Taha | Jordan | 1:00.99 | 8 | 9 | |
| 106 | Talisa Pace | Malta | 1:01.01 | 8 | 0 | |
| 107 | Nilshaira Isenia | Netherlands Antilles | 1:01.12 | 7 | 0 | |
| 108 | Ting Sheng-Yo | Chinese Taipei | 1:01.29 | 9 | 2 | |
| 109 | Shannon Austin | Seychelles | 1:01.38 | 5 | 9 | |
| 110 | Silvie Ketelaars | Netherlands Antilles | 1:01.47 | 8 | 7 | |
| 111 | Andrea Cedron | Peru | 1:01.49 | 6 | 6 | |
| 112 | Sylvia Brunlehner | Kenya | 1:01.56 | 4 | 5 | |
| 113 | Dalia Torrez | Nicaragua | 1:01.68 | 6 | 7 | |
| 114 | Monica Bernardo | Mozambique | 1:01.71 | 5 | 0 | |
| 115 | Ramond Sherazad | Morocco | 1:02.02 | 9 | 9 | |
| 116 | Tan Chi Yan | Macau | 1:02.09 | 6 | 5 | |
| 117 | Judith Ilan Meauri | Papua New Guinea | 1:02.34 | 5 | 7 | |
| 118 | Sophia Noel | Grenada | 1:02.41 | 4 | 2 | |
| 119 | Karla Toscano | Guatemala | 1:02.68 | 5 | 6 | |
| 120 | Anahit Barseghyan | Armenia | 1:02.69 | 4 | 6 | |
| 121 | Long Chi Wun | Macau | 1:02.76 | 6 | 9 | |
| 122 | Kathryn Millin | Eswatini | 1:02.78 | 4 | 7 | |
| 123 | Amanda Jia Xin Liew | Brunei | 1:03.00 | 5 | 1 | |
| 124 | Birita Debes | Faroe Islands | 1:03.10 | 3 | 7 | |
| 125 | Pina Ercolano | Kenya | 1:03.26 | 5 | 8 | |
| 126 | Angelique Trinquier | Monaco | 1:03.32 | 5 | 3 | |
| 127 | Li Chuen Cheong Estelle | Mauritius | 1:03.45 | 3 | 4 | |
| 128 | Ifiezibe Gagbe | Nigeria | 1:03.48 | 3 | 6 | |
| 129 | Rovena Marku | Albania | 1:03.87 | 5 | 5 | |
| 130 | Tin Hon Ko Adeline Mei-Li | Mauritius | 1:03.91 | 6 | 1 | |
| 131 | Ayesha Noel | Grenada | 1:03.96 | 5 | 2 | |
| 132 | Estellah Fils Rabetsara | Madagascar | 1:04.06 | 5 | 4 | |
| 133 | Ouleye Diallo | Senegal | 1:04.07 | 6 | 0 | |
| 134 | Mariana Zaballa | Bolivia | 1:04.37 | 4 | 8 | |
| 135 | Cheyenne Rova | Fiji | 1:04.67 | 4 | 1 | |
| 136 | Amelie Trinquier | Monaco | 1:04.87 | 3 | 3 | |
| 137 | Gessica Stagno | Mozambique | 1:04.94 | 4 | 9 | |
| 138 | Sameera Al Bitar | Bahrain | 1:05.05 | 2 | 4 | |
| 139 | Mareme Faye | Senegal | 1:05.06 | 4 | 3 | |
| 140 | Tieri Erasito | Fiji | 1:05.26 | 3 | 2 | |
| 141 | Yara Dowani | Palestine | 1:06.02 | 3 | 1 | |
| 142 | Julia Alves | Marshall Islands | 1:06.13 | 2 | 6 | |
| 143 | Mirella Alam | Lebanon | 1:06.53 | 4 | 0 | |
| 144 | Maria Grace Koh | Brunei | 1:06.93 | 4 | 4 | |
| 145 | Rachael Catherine Glenister | American Samoa | 1:07.00 | 3 | 5 | |
| 146 | Enkhjargal Khulan | Mongolia | 1:07.07 | 3 | 8 | |
| 147 | Noelle Anyika Smith | Guyana | 1:07.11 | 3 | 9 | |
| 148 | Julianne Kirchner | Marshall Islands | 1:07.84 | 2 | 2 | |
| 149 | Maria Gibbons | Palau | 1:08.21 | 2 | 5 | |
| 150 | Olivia Infield | Uganda | 1:08.31 | 1 | 5 | |
| 151 | Sabine Hazboun | Palestine | 1:08.57 | 3 | 0 | |
| 152 | Mahnoor Maqsood | Pakistan | 1:08.92 | 2 | 3 | |
| 153 | Katerina Izmailova | Tajikistan | 1:09.80 | 2 | 9 | |
| 154 | Osisang Chilton | Palau | 1:10.45 | 2 | 7 | |
| 155 | Rida Mitha | Pakistan | 1:12.62 | 2 | 1 | |
| 156 | Gouri Kotecha | Tanzania | 1:13.14 | 1 | 7 | |
| 157 | Shreya Dhital | Nepal | 1:15.58 | 1 | 4 | |
| 158 | Shaila Rana | Nepal | 1:15.84 | 2 | 0 | |
| 159 | Ismail Aminath Inas | Maldives | 1:18.25 | 1 | 2 | |
| 160 | Jennet Saryyeva | Turkmenistan | 1:18.63 | 1 | 6 | |
| 161 | Irankunda Lena Courageuse | Burundi | 1:18.73 | 1 | 3 | |
| – | Maroua Mathlouthi | Tunisia | DNS | 9 | 5 | |
| – | Dina Hegazy | Egypt | DNS | 10 | 4 | |
| – | Pang Jiaying | China | DNS | 15 | 2 | |
| – | Marleen Veldhuis | Netherlands | DNS | 15 | 4 | |
| – | Federica Pellegrini | Italy | DNS | 16 | 5 | |

### Semifinals

| Rank | Name | Nationality | Time | Heat | Lane | Notes |
| 1 | Libby Trickett | Australia | 52.84 | 1 | 4 | |
| 2 | Britta Steffen | Germany | 52.87 | 1 | 5 | |
| 3 | Amanda Weir | United States | 53.02 | 2 | 4 | AM |
| 4 | Francesca Halsall | Great Britain | 53.05 | 1 | 6 | |
| 5 | Ranomi Kromowidjojo | Netherlands | 53.31 | 2 | 5 | |
| 6 | Jeanette Ottesen | Denmark | 53.41 | 1 | 3 | NR |
| 7 | Dana Vollmer | United States | 53.55 | 2 | 3 | |
| 8 | Evelyn Verrasztó | Hungary | 53.74 | 1 | 2 | NR |
| 9 | Daniela Schreiber | Germany | 53.76 | 2 | 7 | |
| 10 | Hanna-Maria Seppälä | Finland | 53.82 | 2 | 2 | |
| 11 | Hayley Palmer | New Zealand | 53.91 | 2 | 1 | NR |
| 12 | Malia Metella | France | 53.95 | 2 | 6 | |
| 13 | Li Zhesi | China | 53.97 | 1 | 7 | |
| 14 | Marieke Guehrer | Australia | 54.21 | 1 | 8 | |
| 15 | Victoria Poon | Canada | 54.29 | 1 | 1 | |
| 16 | Aleksandra Gerasimenya | Belarus | 54.51 | 2 | 8 | |

### Final

| Rank | Name | Nationality | Time | Lane | Notes |
| | Britta Steffen | Germany | 52.07 | 5 | WR |
| | Francesca Halsall | Great Britain | 52.87 | 6 | NR |
| | Libby Trickett | Australia | 52.93 | 4 | |
| 4 | Amanda Weir | United States | 53.12 | 3 | |
| 5 | Dana Vollmer | United States | 53.30 | 1 | |
| 6 | Ranomi Kromowidjojo | Netherlands | 53.37 | 2 | |
| 7 | Jeanette Ottesen | Denmark | 53.70 | 7 | |
| 8 | Evelyn Verrasztó | Hungary | 53.92 | 8 | |