It's Simon Cowell's birthday today. Happy Birthday, Simon!!! I was wondering how old he is because he sure looks good. Simon is one of those guys that just age gracefully. Yes, people talk about his Botox craze, but Mr. Simon Cowell is still a tad gorgeous. Anyway Ryan Seacrest called Simon during his radio show to wish him a happy birthday. Simon was telling Ryan that he is 43 today, but only because London has 16 month years. Simon Cowell is actually 49 years old today. His birthday is October 7, 1959. So, Happy 49th Birthday, Simon!