Brent Matthew Hayden (born October 21, 1983) is a Canadian former competitive swimmer. Hayden was a bronze medal-winner in the 100-metre freestyle at the 2012 Summer Olympics in London. He was world champion in the same event in 2007 with Filippo Magnini of Italy. By winning the 100-metre, Hayden became the first Canadian in 21 years to win a gold medal at the World Aquatics Championships, he was also the first Canadian to appear in the 100-metre final at the Olympics since Dick Pound at the 1960 Summer Olympics, and the first Canadian to win an Olympic medal in the 100-metre. Hayden adds a further three silver and one bronze medal to his World Championship totals. In addition, Hayden is currently the Canadian record-holder in the 200-metre, 100-metre and 50-metre freestyle in both the short-course and long-course. He has also held the world record in the 4×100-metre medley relay, and the 4×200-metre freestyle relay.
Athens was the location of Hayden's first Olympics when he took part in the 2004 Summer Olympics as part of the Canadian swimming team. It was a disappointing first Olympic appearance for Hayden, as inexperience took its toll on the 20-year-old. It was further worsened when Brent was mistaken for a protester and beaten up and arrested by the riot police because he was "tall and wearing a dark shirt" the night before the Closing Ceremonies, a week after his competition ended. The injuries sustained left him unable to compete at the World Short Course Championships which were being held a month later. His best individual finish in Athens was 13th in the 200-metre freestyle event.
In Melbourne for the 2006 Commonwealth Games, Hayden won his first major international silver medal when he finished second in the 50-metre freestyle, an event he had not intended on racing. He also added three bronze medals at the same games, two from the relays and one in the 200-metre freestyle final. Those medals were a premonition of the success to come for Hayden at the 2007 World Aquatics Championships. There he tied for the gold medal with the Italian swimmer in the 100-meetre freestyle; this was the first World Championship for the Canadians since 1986. In the process of winning the gold, Hayden had also shaved down his own national record in the event down to 48.43 and he also added a bronze from the World's in the 4×200-metre freestyle relay. As a result of his victory, the mayor of Mission declared "Brent Hayden Day" on May 26, 2007. As well, the Mission Marlins renamed their swim meet to the "Brent Hayden Invitational" and a large mural, painted on the wall of the Mission Leisure Center, by artist Pascal A. Pelletier, was unveiled.