Swimming at the 2011 World Aquatics Championships – Women's 100 metre backstroke

The women's 100 metre backstroke competition of the swimming events at the 2011 World Aquatics Championships were held on July 25 with the preliminary round and the semifinals and July 26 with the final.

Records
Prior to the competition, the existing world and championship records were as follows.

Heats
53 swimmers participated in 7 heats, qualified swimmers are listed:

Semifinals
The semifinals were held at 18:46.

Final
The final was held at 18:11.