Brendan Joseph Hansen (born August 15, 1981 in Havertown, Pennsylvania) is an American swimmer who specializes in the breaststroke. He is a four-time Olympic medalist and multiple record holder. He attended Haverford Senior High School in Haverford, PA.
Brendan Hansen grew up in Havertown, PA, a suburb about 10 minutes away from Philadelphia. He swam at many different clubs, some including Karakung Swim Club and Lower Merion Aquatic Club. His main strokes are breaststroke and freestyle. 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.