William J. Ziegler Jr. (July 21, 1891 – March 3, 1958) was an American business executive, philanthropist, polo player, yachtsman, and a Thoroughbred racehorse owner and breeder. Born William Conrad Brandt in Muscatine, Iowa to the half-brother of William Ziegler who adopted the boy at age 5 and renamed him William Ziegler Jr. After his mother, Matilda, died, he took over her Matilda Ziegler Magazine for the Blind publishing, American Foundation for the Blind, and other charities.