They all posed for a picture together ahead of the first set of auditions, with host Dermot O'Leary, who posted it on Twitter.
"And so it begins..." he wrote alongside the snap.
Sharon was causing a stir before she'd even taken to her judges chair, as her arrival in the building was typically understated.
The official 'X Factor' Twitter account teased her entrance, writing: "And let's just say Sharon's entrance to The X Factor HQ (complete with muscle-bound, kilt-clad hunks!) will take some beating!"
Not only has Sharon replaced Tulisa on the panel, but there will be some other big changes to the new series of the show, as the old 'judges room' auditions are also making a return.
Hopefuls will faces the judges in an intimate room - as in the first five series of the show - before going on to a second audition held in an arena.
The new series will hit screens in the autumn.