The Men's 50 Backstroke event at the 11th FINA World Aquatics Championships swam on 30 – 31 July 2005 in Montreal, Canada.

Preliminary[1] and Semifinal[2] heats swam on 30 July; the Final[3] was 31 July.

Prior to the start of the event, the existing World (WR) and Championship (CR) records were both: