John Randolph Anthony (1890–1954), better known as Jack Anthony, was a Welsh jockey.
Anthony was best known for his three victories in the Grand National steeplechase: on "Glenside" in 1911, on "Ally Sloper" in 1915, and on "Troytown" in 1920. He was the sixth jockey to win three Grand Nationals, and also finished third in the 1925 event.
He came from a horse racing family, his brother Ivor also being a successful jockey and his brother Owen a trainer. Jack rode his first winner in 1906, and was an amateur until 1921. He was champion jockey on two occasions, in 1914 and 1928. In the latter year, he retired from riding to become a trainer. His biggest success as a trainer was with Easter Hero, which won the Cheltenham Gold Cup in 1929 and 1930.
In 1991 he was included in the Welsh Sports Hall of Fame.