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

The men's 100 m freestyle at the 2009 World Championships took place on 29 July (heats and semifinals) and the evening of 30 July (finals) 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 men's 4 × 100 m freestyle relay