The men's 50 metre backstroke event at the 2005 World Aquatics Championships took place between 30 July – 31 July. The heats and semifinals were held on 30 July. The final was held on 31 July.

Records

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

	Name	Nationality	Time	Location	Date
World record	Thomas Rupprath Thomas Rupprath Thomas Rupprath is an Olympic swimmer from Germany, who is nicknamed "The New Albatross". A specialist in the backstroke and butterfly, especially in short course, he held the world record for the 50 m backstroke with a time of 23.27 seconds set on 31 November 2002. This was broken by Robert...	Germany Germany Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...	24.80	Barcelona Barcelona Barcelona is the second largest city in Spain after Madrid, and the capital of Catalonia, with a population of 1,621,537 within its administrative limits on a land area of...	27 July 2003
Championship record	Thomas Rupprath Thomas Rupprath Thomas Rupprath is an Olympic swimmer from Germany, who is nicknamed "The New Albatross". A specialist in the backstroke and butterfly, especially in short course, he held the world record for the 50 m backstroke with a time of 23.27 seconds set on 31 November 2002. This was broken by Robert...	Germany Germany Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...	24.80	Barcelona Barcelona Barcelona is the second largest city in Spain after Madrid, and the capital of Catalonia, with a population of 1,621,537 within its administrative limits on a land area of...	27 July 2003

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

Final

Rank	Name	Nationality	Time	Notes
	Aristeidis Grigoriadis Aristeidis Grigoriadis Aristeidis Grigoriadis is a Greek swimmer from Thessaloniki.-Career:Grigoriadis was the first Greek swimmer to be crowned world champion in the 50 m backstroke event of the 2005 World Championships in Montreal...		24.95
	Matt Welsh Matt Welsh Matthew "Matt" Welsh is an Australian swimmer who is the former world champion in the backstroke and butterfly. Welsh trained under coach Ian Pope at the Melbourne Vicentre Club. He took two golds in 50 metres butterfly and 50 metres backstroke, during one hour, at the World Championships in...		24.99
	Liam Tancock Liam Tancock Liam John Tancock is an English backstroke swimmer who specializes in the 50 m and 100 m events. He began his swimming career at Exeter City Swimming Club in Devon and continued at Loughborough University where he studied sports science...		25.02
4	Randall Bal Randall Bal Randall Bal is an American swimmer who specializes in the backstroke. He is a former world record holder in the 50-meter backstroke ....		25.23
5	Aaron Peirsol Aaron Peirsol Aaron Wells Peirsol is a former American swimmer who specialized in the backstroke. He is a three-time Olympian and seven-time Olympic medalist . As part of the American team, he holds the world record in the 4×100-meter medley relay...		25.30
6	Thomas Rupprath Thomas Rupprath Thomas Rupprath is an Olympic swimmer from Germany, who is nicknamed "The New Albatross". A specialist in the backstroke and butterfly, especially in short course, he held the world record for the 50 m backstroke with a time of 23.27 seconds set on 31 November 2002. This was broken by Robert...		25.38
7	Junichi Miyashita Junichi Miyashita is a Japanese swimmer. He won a bronze medal in the men's 4 × 100 metre medley relay at the 2008 Summer Olympics.-External links:*...		25.85
8	Marco Di Carli Marco di Carli Marco di Carli is a German swimmer who specialisms are backstroke and freestyle. He swims at the SG Frankfurt club and is 1.89 metres tall and weighs 80 kg ....		26.48