The women's 100 metre breaststroke 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.

	Name	Nationality	Time	Location	Date
World record	Leisel Jones Leisel Jones Leisel Marie Jones OAM is an Australian Olympic gold medalist swimmer. A participant in the 2000 Summer Olympics – at just 15 years old – and 2004 Summer Olympics, she was part of gold medal winning Australian team in the women's 4 × 100 metre medley relay at the Athens Games in 2004 and a gold...	Australia Australia Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...	1:06.37	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...	21 July 2003
Championship record	Leisel Jones Leisel Jones Leisel Marie Jones OAM is an Australian Olympic gold medalist swimmer. A participant in the 2000 Summer Olympics – at just 15 years old – and 2004 Summer Olympics, she was part of gold medal winning Australian team in the women's 4 × 100 metre medley relay at the Athens Games in 2004 and a gold...	Australia Australia Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...	1:06.37	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...	21 July 2003

The following records were established during the competition:

Date	Round	Name	Nationality	Time	WR	CR
July 25	Semifinals	Jessica Hardy Jessica Hardy Jessica Adele Hardy is an American swimmer who specializes in the breaststroke and freestyle stroke. She currently holds the world record in the 50 m breaststroke and the 100 m breaststroke ....	United States United States The United States of America is a federal constitutional republic comprising fifty states and a federal district...	1:06.20	WR	CR

Final

Rank	Name	Nationality	Time	Notes
	Leisel Jones Leisel Jones Leisel Marie Jones OAM is an Australian Olympic gold medalist swimmer. A participant in the 2000 Summer Olympics – at just 15 years old – and 2004 Summer Olympics, she was part of gold medal winning Australian team in the women's 4 × 100 metre medley relay at the Athens Games in 2004 and a gold...		1:06.25
	Jessica Hardy Jessica Hardy Jessica Adele Hardy is an American swimmer who specializes in the breaststroke and freestyle stroke. She currently holds the world record in the 50 m breaststroke and the 100 m breaststroke ....		1:06.62
	Tara Kirk Tara Kirk Tara Kirk is a former American swimmer who specialized in the breaststroke and Olympic silver medalist. She is a former world record holder in the 100-meter breaststroke ....		1:07.43
4	Luo Xuejuan Luo Xuejuan Luo Xuejuan is a female Chinese swimmer, who competed mostly in the breaststroke. She is a former World Record holder in swimming, and in some meet results she is listed as "LUO Xue Juan".-Career:...		1:07.60
5	Brooke Hanson Brooke Hanson Brooke Louise Hanson OAM is a former Australian swimmer.A swimmer since the age of four, Hanson was the youngest swimmer on the Australian national team at the 1994 Commonwealth Games, where she finished fourth in the 200 m breaststroke...		1:08.07
6	Suzaan Van Biljon Suzaan van Biljon Suzaan van Biljon is an Olympic-swimmer from South Africa. She swam for South Africa at the 2008 Olympics, and as of June 2009 holds both African and South African records.-External links:*...		1:08.38
7	Sarah Poewe Sarah Poewe Sarah Poewe is an Olympic Breaststroke swimmer, who has swum internationally for both South Africa and Germany....		1:08.47
8	Chiara Boggiatto Chiara Boggiatto Chiara Boggiatto is an Italian breaststroke swimmer. She was several times finalist in European and World Championship swimming 200 m breaststroke and relays...		1:08.98