Demi Lovato Joins “X Factor”

It's official...Demi Lovato is "The X Factor"'s newest celebrity judge!

She joins Simon Cowell, L.A. Reid and just-announced addition Britney Spears at the judges' table when the show returns this fall on Fox.

Fox has yet to comment on Lovato's signing, but she and Spears are expected to make an appearance at the network's upfront presentation Monday.