Triple Crown

(baseball) The feat of leading one's league in three key statistical categories—batting average, home runs, and RBI for hitters; wins, strikeouts, and ERA for pitchers

(golf) The three grandest or oldest open championships of the year

(in men's golf) The U.S. Open, British Open, Canadian Open

(horse racing, US) The three greatest thoroughbred races of the year restricted to three-year-olds: the Kentucky Derby, Preakness Stakes, and Belmont Stakes

(horse racing, UK) The three greatest thoroughbred races of the year restricted to three-year-olds: the 2,000 Guineas Stakes, Derby Stakes (aka "Epsom Derby"), and St. Leger Stakes

(horse racing, Canada) The three greatest thoroughbred races of the year restricted to three-year-olds: the Queen's Plate, Prince of Wales Stakes, and Breeders' Stakes

(rugby) Victory by one of the Home Nations — England, Ireland, Scotland, Wales — over the other three in the annual Six Nations Championship.

(motorsports) Victory by a driver at the three grandest car races in the world, the Indianapolis 500, 24-Hours of Le Mans, Monaco Grand Prix; usually defined as a career achievement and not a season or calendar year achievement