Swimming at the 2005 World Aquatics Championships – Men's 100 metre backstroke

The men's 100 metre backstroke event at the 2005 World Aquatics Championships took place between 25 July – 26 July. Both the heats and semifinals were held on 25 July with the heats being held in the morning session and the semifinals being held in the evening session. The final was held on 26 July.

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

No new world or competition records were set during this competition.