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:

The following records were established during the competition:

* Split from the women's 4 × 100 m freestyle relay