Swimming at the 2005 World Aquatics Championships – Women's 100 metre backstroke
The Women's 100 Backstroke at the 11th FINA World Aquatics Championships was swum 25 - 26 July 2005 in Montreal, Quebec, Canada. Preliminary and Semifinal heats were 25 July; the Final heat on 26 July.
At the start of the event, the existing World and Championships records were:
Preliminaries
Semifinals
Final
| Place | Swimmer | Nation | Time | Notes |
| Kirsty Coventry |  Zimbabwe | 1:00.24 | |
| Antje Buschschulte |  Germany | 1:00.84 | |
| Natalie Coughlin |  USA | 1:00.88 | |
| 4 | Reiko Nakamura |  Japan | 1:01.00 | |
| 5 | Hannah McLean |  New Zealand | 1:01.16 | |
| 6 | Hanae Ito | Japan | 1:01.25 | |
| 7 | Louise Ørnstedt |  Denmark | 1:01.36 | |
| 8 | Sophie Edington |  Australia | 1:01.97 | |
