"It's taken more than a decade, but I'm delighted to finally be on a panel with three girls... Paulina and Kelly both have great taste and massive experience in the music industry and together with Demi, this is going to be a fun panel," Cowell said in a statement.
Rowland, 32, formerly of Destiny's Child, was a judge on season eight of Britain's "The X Factor." "I am very excited to be reuniting with Simon Cowell and 'The X Factor' family," Rowland said in a statement. "It feels great to be able to take this journey here at home in the States!"
Rubio, 41, who was raised in Mexico and has sold more than 20 million albums worldwide, added, "I can't wait to find the next big music star here in America."