Natalie Anne Coughlin Hall (born August 23, 1982) is an American former competition swimmer and twelve-time Olympic medalist. While attending the University of California, Berkeley, she became the first woman ever to swim the 100-meter backstroke (long course) in less than one minute. At the 2008 Summer Olympics, she became the first U.S. female athlete in modern Olympic history to win six medals in one Olympiad, and the first woman ever to win a 100-meter backstroke gold in two consecutive Olympics. At the 2012 Summer Olympics, in her third and final Olympic appearance, she earned a bronze medal in the 4×100-meter freestyle relay.

Coughlin's success has earned her the World Swimmer of the Year Award once and American Swimmer of the Year Award three times. She has won a total of sixty medals in major international competition, twenty-five gold, twenty-two silver, and thirteen bronze spanning the Olympics, the World, the Pan Pacific Championships, and the Pan American Games.

Coughlin was born in Vallejo, California, the daughter of Jim and Zennie Coughlin. She is of Irish and one quarter Filipino ancestry. Coughlin first began swimming at Vallejo Aquatics Club when she was 8 years old, where she was coached by Tuffy Williams. She attended St. Catherine of Siena School in Vallejo, for kindergarten through eighth grade, and then Carondelet High School in Concord, California. While in high school in 1998, she became the first swimmer to qualify for the Summer National in all fourteen events. Coughlin broke two individual national high school records in the 200-yard individual medley (1:58.45) and the 100-yard backstroke (52.86). She graduated from Carondelet High School in 2000.

Coughlin attended the University of California, Berkeley, where she swam for coach Teri McKeever's California Golden Bears swimming and diving team in National Collegiate Athletic Association (NCAA) competition from 2001 to 2004. During her four years as a Cal Bears swimmer, she won eleven individual NCAA national championships, and a twelfth NCAA relay title. She was recognized as the NCAA Swimmer of the Year for three consecutive years, and she was a two-time recipient of the Honda Sports Award for Swimming and Diving, recognizing her as the outstanding college female swimmer in 2001–02 and 2002–03. Sports Illustrated magazine named her its college Female Athlete of the Year. Coughlin was inducted into the Cal Athletic Hall of Fame in 2014. Coughlin graduated from Berkeley with a degree in psychology in the spring of 2005.

At the ninth World Aquatics Championships in Fukuoka, Japan, Coughlin won three medals—one gold, one silver, and one bronze. She won her gold medal in the 100-meter backstroke with Diana Mocanu (Romania) taking the silver and Antje Buschschulte (Germany) taking the bronze. Coughlin won her silver medal in the women's 4×100-meter medley relay, teaming up with Megan Quann, Mary Descenza, and Erin Phenix; the Australians won the gold (Calub, Jones, Thomas, Ryan). Coughlin won her bronze medal in the 50-meter backstroke; fellow American Haley Cope won gold and Antje Buschschulte won the silver.

At the ninth Pan Pacific Championships in Yokohama, Japan, Coughlin won six medals—four golds and two silvers. Coughlin won one of her gold medals in the women's 100-meter backstroke with a time of 59.72, and another in the women's 100-meter butterfly with a time of 57.88. Coughlin won her third gold medal in the women's 100-meter freestyle with a time of 53.99. She won her fourth gold medal in the women's 4×200-meter freestyle relay with Elizabeth Hill, Diana Munz, and Lindsay Benko. She won her silver medals as a member of the second-place U.S. relay teams in the 4×100-meter freestyle and 4×100-meter medley events.

At the tenth World Aquatics Championships in Barcelona, Spain, Coughlin won two medals, including a gold and a silver. Coughlin won her gold medal in the women's 4×100-meter freestyle relay and a silver medal in the 4×100-medley relay.

Coughlin won the gold medal at the 2004 Olympics in the women's 100-meter backstroke event and won a silver medal as a member of the U.S. women's 4×100-meter freestyle relay team with Kara Lynn Joyce, Amanda Weir and Jenny Thompson. She also broke a world record and won gold as a member of the 4×200-meter freestyle relay, a silver in the 4×100-meter medley relay, and a bronze in the 100-meter freestyle.