Swimming at the 2007 World Aquatics Championships – Women's 800 metre freestyle

The Women's 800m Freestyle at the 2007 World Aquatics Championships took place on the morning of 30 March (prelims) and the evening of 31 March (finals) at the Rod Laver Arena in Melbourne, Australia.

The existing records when the event started were:
 * World Record (WR): 8:16.22, Janet Evans (USA), 20 August 1989 in Tokyo, Japan.
 * Championship Record (CR): 8:23.66, Hannah Stockbauer (Germany), Barcelona 2003 (Jul.26.2003)