Swimming at the 2004 Summer Olympics – Women's 100 metre butterfly

The women's 100 metre butterfly event at the 2004 Olympic Games was contested at the Olympic Aquatic Centre of the Athens Olympic Sports Complex in Athens, Greece on August 14 and 15.

Australia's Petria Thomas, who finished fourth in Sydney, won her first individual gold medal in this event, outside the Olympic record time of 57.72 seconds. The silver medal was awarded to Poland's Otylia Jędrzejczak, who trailed behind Thomas by 0.12 of a second, in an outstanding time of 57.84. Defending Olympic champion and world record holder Inge de Bruijn of the Netherlands, on the other hand, took home the bronze at 57.99 seconds.