Arthur Allyn, Jr. (December 24, 1913 in Chicago, Illinois – March 22, 1985 in Sarasota, Florida) was the co-owner of the Chicago White Sox of the American League with his brother John Allyn from 1961 through 1969. A few years after purchasing the franchise from Bill Veeck, Allyn tried to sell the team to a number of different parties, including Lamar Hunt and Bud Selig (who planned to move the team to Milwaukee, Wisconsin), before selling his share of the White Sox to his co-owner and brother John. Allyn also owned Chicago Mustangs soccer club that were charter members of the United Soccer Association in 1967. The Mustangs became part of the newly formed North American Soccer League the following year after merging with the NPSL.