Spinell was born Joseph J. Spagnuolo (Italian pronunciation: [spaˈɲɲwɔlo]) in Manhattan, New York, of Italian immigrant parents, and the last of six children. His father, Pelegrino Spagnuolo (1892–1950), died from liver and kidney disease. His mother, Filomena Spagnuolo (1903–1987), was a bit-part Actress who acted in a few movies, some of them alongside her son. Spinell stood 5 foot and 11 inches. He was born at his family's apartment on Second Avenue in Manhattan's Kip's Bay, an area then home to 10,000 Italian Americans. A few years after the death of his father, he moved with his mother and older siblings to Woodside, Queens, New York where he lived off-and-on for the remainder of his life. He was known to abuse drugs and alcohol heavily on and off throughout his career, especially during periods of unemployment. Spinell also suffered most of his life from hemophilia as well as chronic asthma.