Lewis was born at All Saints Maternity Hospital in Poplar, London, England. He worked as a bricklayer, electrician's mate and carpenter and also joined the Merchant Navy before turning to acting. He was persuaded to go to a performance by the Theatre Workshop, under their director Joan Littlewood. It was common, after these performances, to invite members of the audience to meet the cast. He was invited to an audition, landed the part, and left the sea to become a member of the company.