Creelman's father was born to an Ulster-Scottish family who migrated to Montreal from Limavady, Ireland. His mother was of Scottish descent.
James Creelman was born on November 12, 1859 Montreal, Quebec, Canada, the son of a boiler inspector, Matthew Creelman, and homemaker, Martha (née) Dunwoodie. He proved his independence and self-sufficiency early. His parents separated when he was a child, and at only twelve years old he left Montreal and journeyed four hundred miles on foot to be with his mother in New York City. According to Ronald S. Marmarelli in the Dictionary of Literary Biography, he "arrived at his mother's rooming house with worn-out shoes and a nickel in his pocket."