Kardashian and Lopez will begin their hosting duties in November.
"Keeping Up With the Kardashians" star Kardashian and "Extra" host Lopez had long been reported as contenders for the gig, a fact that "X Factor" executive producer and judge Simon Cowell acknowledged in the announcement.
“The worst kept secret in Hollywood is out,” Cowell cracked. “Mario and Khloé are our hosts. They will debut on our first live show in November and I couldn’t be happier.”
“I’m so thrilled to become a part of 'The X Factor' family,” Kardashian said. “I’ve been a big fan of the show and look forward to working with Simon and all of the judges. It’s going to be so much fun!”
Lopez added, "I’ve been a big fan of Simon Cowell and the judges for a long time. Khloé and I have been friends for years and I know we’ll be a great team and have a blast.”
Steve Jones, the host on the first season of "The X Factor," was let go earlier this year during a bloodbath that also saw the ouster of Paula Abdul and Nicole Scherzinger.
Abdul and Scherzinger were replaced by Britney Spears and Demi Lovato for the current second season.
