Gertrude Caroline Ederle (/ˈɛdərli/; October 23, 1905 – November 30, 2003) was an American competition swimmer, Olympic champion, and world record-holder in five events. On August 6, 1926, she became the first woman to swim across the English Channel. Among other nicknames, the press called her "Queen of the Waves".

Ederle grew up in Manhattan where her father ran a butcher shop on Amsterdam Avenue, and learned to swim in Highlands, New Jersey. She later trained at the Women's Swimming Association (WSA), founded by Charlotte Epstein. The WSA was a historic organization whose leadership and members campaigned for Women's suffrage, and worked both to create more swimming events open to women and to increase their participation in the Olympics. Ederle joined the club when she was only twelve and immediately took to learning the American crawl, developed at the WSA by Head Coach Louis Handley. The same year, she set her first world record in the 880-yard freestyle, becoming the youngest world record holder in swimming. She set eight more world records after that, seven of them in 1922 at Brighton Beach. In total, Ederle held 29 US national and world records from 1921 until 1925.

At the 1924 Summer Olympics in Paris, Ederle won a gold medal as a member of the U.S. team in the 4×100 meter freestyle relay. She and teammates Euphrasia Donnelly, Ethel Lackie, and Mariechen Wehselau set a world record of 4:58.8 in the event final. Individually, she received bronze medals in the women's 100-meter freestyle and women's 400-meter freestyle races. The U.S. Olympic team was given a ticker-tape parade in 1924.

In 1925, Ederle turned professional, swimming the 22 miles (35 km) from Battery Park to Sandy Hook in 7 hours and 11 minutes, a record that stood for 81 years before being broken by Australian swimmer Tammy van Wisse. Ederle's nephew Bob later described his aunt's swim as a "midnight frolic" and a "warm-up" for her later swim across the English Channel.

In 1925, the Women's Swimming Association sponsored Helen Wainwright and Ederle in an attempt at swimming across the English Channel. Helen Wainwright cancelled due to an injury, but Ederle decided to try the crossing on her own. She trained with Jabez Wolffe, who had attempted 22 times to swim the Channel. On August 18, 1925, Ederle made her first attempt, but was disqualified when Wolffe ordered another swimmer, Ishak Helmy, to recover her from the water. She bitterly disagreed with Wolffe's decision and it was speculated that he did not want Ederle to succeed.

She returned to New York and began training with coach Bill Burgess, who had successfully swum the Channel in 1911. Ederle also received a contract from both the New York Daily News and Chicago Tribune that paid her expenses and provided her with a modest salary. Approximately one year after her first attempt, she was successful. She started at Cap Gris-Nez in France at 07:08 am on August 6, 1926, and came ashore at Kingsdown, Kent, 14 hours and 34 minutes later. The first person to greet her was a British immigration officer who requested a passport from "the bleary-eyed, waterlogged teenager". Her record stood until Florence Chadwick swam the Channel in 1950 in 13 hours and 23 minutes.

Prior to Ederle, only five men had completed the swim across the English Channel, with the best time of 16 hours, 33 minutes by Enrique Tirabocchi.

When Ederle returned home, she was greeted with a ticker-tape parade in Manhattan, with more than two million people along the parade route.