Winstone was born on 19 February 1957 in Hackney Hospital, London. He first lived in Caister Park Road, Plaistow E13, and attended Portway infants and junior school. He moved to Enfield when he was seven and grew up on a council estate just off the A10 road. His father, Raymond J. Winstone (1933–2015), ran a fruit and vegetable business while his mother, Margaret (née Richardson; 1932–1985) had a job emptying fruit machines. Winstone has recounted how, as a child, he used to play with his friends on bomb sites (vacant lots with rubble from World War II bombs). He joined Brimsdown Primary School and later he was educated at Edmonton County School which had changed from a grammar school to a comprehensive upon his arrival. He also attended Corona Theatre School. He did not take to school, eventually leaving with a single CSE (Grade 2) in Drama. He recounted an early encounter with a notorious gangster:
Winstone had an early affinity for acting; his father would take him to the cinema every Wednesday afternoon. Later, he viewed Albert Finney in Saturday Night and Sunday Morning, and said: "I thought, 'I could be that geezer'." Other major influences included John Wayne, James Cagney, and Edward G. Robinson. After borrowing extra tuition money from a friend's mother, a drama teacher, Winstone took to the stage, appearing as a Cockney newspaper seller in a production of Emil and the Detectives.
Winstone was also a fan of boxing. Known to his friends as Winnie, he was called Little Sugs at home (his father already being known as Sugar, after Sugar Ray Robinson). At the age of 12, Winstone joined the Repton Amateur Boxing Club. Over the next 10 years, he won 80 out of 88 bouts. At welterweight, he was London schoolboy champion on three occasions, fighting twice for England. The experience gave him a perspective on his later career: "If you can get in a ring with 2,000 people watching and be smacked around by another guy, then walking onstage isn't hard."
