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

The heats for the Women's 100 m Backstroke race at the 2009 World Championships took place in the morning and evening of 27 July and the final took place in the evening session of 28 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: