Brendan Joseph Hansen (born August 15, 1981 in Havertown, Pennsylvania) is an American swimmer who specializes in the breaststroke. He is 6'0" (183 cm) tall and weighs 189 lb (86 kg).

Despite setting the world record in the 100 and 200 meter breaststroke at the 2004 U.S. Olympic trials, he did not manage to win a gold medal in either event at the 2004 Summer Olympics, as he settled for silver in the 100 and bronze in the 200. He would win a gold in those games for his role in the world-record setting 4 x 100 medley relay. His split on the relay turned out to be one of the fastest in history.

At the 2005 World Aquatics Championships, Hansen won gold in the same three events that he participated in at the 2004 Olympics.

Hansen's well-known for his unique style of breaststroke, which incorporates a kick that is much narrower than the other swimmers, including his biggest rival, Kosuke Kitajima from Japan, who took gold in both the 100 m and 200 m Breaststroke in 2004 Athens Olympic Games. However, Hansen owns the long course World Records in both events.

At the 2006 ConocoPhillips National Championships, Hansen lowered both his world records in the 100 meter and 200 meter breaststroke to 59.13 in the 100 m and 2:08.74 in the 200 m.

At the 2006 Pan Pacific Swimming Championships held in Victoria, Canada blank">http://www.panpacs2006.com/, Hansen again lowered his world record time in the 200 m breaststroke to 2:08.50. It is notable that he was a quarter of a second behind his best time at the 150 m mark, but he came back 0.6 second faster with a 33.38.

Hansen has set numerous NCAA records while swimming for the _University of Texas at Austin. He graduated in 2005 with a degree in kinesiology.

He was also NCAA Champion in the 100 yard and 200 yard breaststroke events each year of his four year college career.