Swimming at the 2013 World Aquatics Championships – Women's 800 metre freestyle
The women's 800 metre freestyle event in swimming at the 2013 World Aquatics Championships took place on 2–3 August at the Palau Sant Jordi in Barcelona, Spain.Records
Prior to this competition, the existing world and championship records were:
The following new records were set during this competition.
| Date | Event | Name | Nationality | Time | Record |
| 3 August | Final | Katie Ledecky | | 8:13.86 | , CR |
Results
Heats
The heats were held at 2 August.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 4 | 4 | Katie Ledecky | | | Q |
| 2 | 2 | 5 | Lauren Boyle | | | Q, OC |
| 3 | 4 | 5 | Lotte Friis | | | Q |
| 4 | 2 | 4 | Mireia Belmonte | | | Q |
| 5 | 3 | 3 | Boglárka Kapás | | | Q |
| 6 | 3 | 7 | Martina de Memme | | | Q |
| 7 | 3 | 6 | Andreina Pinto | | | Q |
| 8 | 4 | 3 | Chloe Sutton | | | Q |
| 9 | 3 | 4 | Jazmin Carlin | | | |
| 10 | 2 | 3 | Jessica Ashwood | | | |
| 11 | 2 | 2 | Kristel Köbrich | | | |
| 12 | 4 | 2 | Shao Yiwen | | | |
| 13 | 3 | 2 | Alexa Komarnycky | | | |
| 14 | 3 | 5 | Xu Danlu | | | |
| 15 | 3 | 1 | Sarah Köhler | | | |
| 16 | 3 | 0 | Samantha Arevalo | | | NR |
| 17 | 4 | 6 | Eleanor Faulkner | | | |
| 18 | 4 | 1 | Isabelle Härle | | | |
| 19 | 2 | 6 | Beatriz Gómez Cortes | | | |
| 20 | 4 | 7 | Savannah King | | | |
| 21 | 2 | 1 | Julia Hassler | | | |
| 22 | 4 | 0 | Susana Escobar | | | |
| 23 | 2 | 8 | Tjasa Oder | | | |
| 24 | 4 | 8 | Katya Bachrouche | | | |
| 25 | 3 | 9 | Khoo Cai Lin | | | |
| 26 | 3 | 8 | Carolina Bilich | | | |
| 27 | 4 | 9 | Virginia Bardach | | | |
| 28 | 2 | 0 | Kyna Pereira | | | |
| 29 | 2 | 9 | Andrea Basaraba | | | |
| 30 | 1 | 6 | Valerie Gruest | | | |
| 31 | 1 | 4 | | | | |
| 32 | 1 | 3 | Lani Cabrera | | | |
| 33 | 1 | 5 | Raina Ramdhani | | | |
| 34 | 1 | 2 | Daniela Miyahara | | | |
| 35 | 1 | 7 | Daniela Benavides | | | |
| 36 | 1 | 8 | San Khant Khant Su | | 10:03.20 | |
| 37 | 1 | 1 | Monica Saili | | 10:11.46 | |
| 38 | 1 | 0 | Victoria Chentsova | | 10:14.63 | |
| 2 | 7 | Camille Muffat | | | |
Final
The final was held at 19:26.
| Rank | Lane | Name | Nationality | Time | Notes |
| 4 | Katie Ledecky | | 8:13.86 | |
| 3 | Lotte Friis | | 8:16.32 | |
| 5 | Lauren Boyle | | 8:18.58 | OC |
| 4 | 2 | Boglárka Kapás | | 8:21.21 | NR |
| 5 | 6 | Mireia Belmonte | | 8:21.99 | |
| 6 | 8 | Chloe Sutton | | 8:27.75 | |
| 7 | 1 | Andreina Pinto | | 8:29.37 | |
| 8 | 7 | Martina de Memme | | 8:37.29 | |
