Kenneth Leroy Roberts (born December 31, 1951 in Modesto, California) is an American former professional motorcycle racer and racing team owner. In 1978, he became the first American to win a Grand Prix motorcycle racing world championship. He was also a two-time winner of the A.M.A. Grand National Championship. Roberts is one of only four riders in American Motorcyclist Association (AMA) racing history to win the AMA Grand Slam, representing Grand National wins at a mile, half-mile, short-track, TT Steeplechase and road race events.
Roberts left his mark on Grand Prix motorcycle racing as a world championship winning rider, an advocate for increased safety standards in racing, and as a racing team owner and a motorcycle engine and chassis constructor. His dirt track-based riding style changed the way Grand Prix motorcycles were ridden. Roberts' proposal to create a rival motorcycle championship in 1979 broke the Fédération Internationale de Motocyclisme (FIM) hegemony and increased the political clout of Grand Prix racers, which subsequently led to improved safety standards and a new era of professionalism in the sport. In 2000, Roberts was named a Grand Prix Legend by the FIM.