Gregory James LeMond (born June 26, 1961) is an American former professional road racing cyclist, entrepreneur, and anti-doping advocate. A two-time winner of the Road Race World Championship (1983 and 1989) and a three-time winner of the Tour de France (1986, 1989, and 1990), LeMond is considered by many to be the greatest American cyclist of all time, one of the great all-round cyclists of the modern era, and an icon of the sport's globalisation.

LeMond began his professional cycling career in 1981. In 1983, he became the first American male cyclist to win the Road World Championship. LeMond won the Tour de France in 1986; he is the first non-European professional cyclist to win the Tour. He was accidentally shot with pellets and seriously injured while hunting in 1987. Following the shooting, he underwent two surgeries and missed the next two Tours. At the 1989 Tour, he completed an improbable comeback to win in dramatic fashion on the race's final stage. He successfully defended his Tour title the following year, becoming one of only eight riders to win three or more Tours. LeMond retired from competition in December 1994 and was inducted into the United States Bicycling Hall of Fame in 1996. He was the first professional cyclist to sign a million-dollar contract and the first cyclist to appear on the cover of Sports Illustrated.

During his career, LeMond championed several technological advancements in pro cycling, including the introduction of aerodynamic "triathlon" handlebars and carbon fiber bicycle frames, which he later marketed through his company LeMond Bicycles. His other business interests have included restaurants, real estate, and consumer fitness equipment. LeMond is a vocal opponent of performance-enhancing drug use in cycling and is a founding board member of 1in6.org, a nonprofit charity that assists male victims of child sex abuse.