The music mogul took poll position after earning a staggering £50 million in the last year - £15 million more than Cowell's earnings in 2008.
His latest accolade is proof the 50-year-old star's success shows no sign of ending anytime soon. A $1 billion deal with Sony will see him take part-ownership of his label Syco, entitling him to 50% of its profits, the ability to sell the X Factor and Britain’s Got Talent formats to even more countries (making Cowell an estimated £500 million by 2012), and gives Cowell joint control of artists produced by the shows, including Leona Lewis, Alexandra Burke and Susan Boyle, whose debut album was the fastest-selling record in history.