Fritzie Zivic, born as Ferdinand Henry John Zivcich, was an American boxer who held the world welterweight championship from October 4, 1940, until July 29, 1941. His managers included Luke Carney, and later, after 1942, Louis Stokan.

John A. Zivic was an American boxer who competed in the featherweight class in the 1920 Summer Olympics in Antwerp. He was a serious contender for the world lightweight championship in 1924, but was defeated by reigning junior lightweight champion Jack Bernstein in an elimination tournament. He had a solid punch and was known for his left hook.