The National Western Stock Show is a livestock show and festival held annually every January at the National Western Complex in Denver, Colorado since 1906.
Its original purpose was to demonstrate better breeding and feeding techniques to area stockmen. The founders included Elias M. Ammons, president of the Colorado Cattle and Horse Growers Association and later governor of Colorado; George Ballentine, general manager of the Denver Union Stock Yard Company; and Fred P. Johnson, publisher of the Record Stockman. Since first held in 1906, it has become the world's largest stock show by number of animals and offers the world's only carload and pen cattle show.
Originally limited to the livestock from the western United States, the show was expanded by 1908 to include entrants from around the world. A horse show was included as an annual event in 1908, and a rodeo was added in 1931. By 1925, an event for 4-H, the 4-H Roundup, was also held in conjunction with the stock show. By 1981 the organization owned numerous buildings, more than twenty acres of stockyards, several acres of parking, and total assets of about five million dollars.