Jack Sharkey (October 26, 1902 – August 17, 1994) was an American heavyweight boxing champion. He was born Joseph Paul Zukauskas (his birth surname is sometimes given as Cukoschay), the son of Lithuanian immigrants, in Binghamton, New York but moved to Boston, Massachusetts as a young man. Sources report little of his early life until, at the outset of the First World War, teenaged Joseph repeatedly tried to enlist in the Navy. Turned down because of his age, he was not able to enlist until after the end of the war.