Steadman was born in Wallasey, Cheshire, and brought up in Towyn, North Wales. He went to Ysgol Emrys Ap Iwan (high school), Abergele, East Ham Technical College and the London College of Printing during the 1960s. There, he did freelance work for "Punch", "Private Eye", the "Daily Telegraph," "The New York Times" and "Rolling Stone".