James T. Ellison, better known as Biff Ellison, was a New York City gangster affiliated with the Five Points Gang and later a leader of the Gopher Gang. He was noted for his propensity for physical violence as well as a dapper appearance that led The New York Times to describe him as "looking like a prosperous banker or broker" and contemporary chroniclers as "smooth-faced, high-featured, well-dressed, a Gangland cavalier" and "a fop in matters of dress".
Ellison was closely associated with gangster Jack Sirocco during the wars against the Eastman Gang during the early 1900s. In addition to running protection rackets that reputedly gained him a handsome annual income of somewhere between $2,000 and $3,000, Ellison owned or managed several bars and gambling establishments in New York City, including the gay bar and brothel Columbia Hall and an illegal pool hall occupying the basement of Ellison's residence at 231 East 14th Street. His nickname, Biff, was a period synonym for "punch" or "hit", and it was coined in response to a youthful fight in which Ellison, then working as a bartender, knocked unconscious a customer who refused to pay for a beer. He was also known as Young Biff, Fourteenth Street Biff, and Biff Ellison II to distinguish him from Frank "Biff" Ellison, a minor Manhattan society figure who had been convicted of assault in 1893 and sent to Sing Sing prison.