Spears tweeted a 15-second teaser on Viddy, before uploading the full 30-second clip to YouTube.
The trailer shows footage of Spears offering advice to auditionees, including telling one contestant "'you have a really nice soothing sound and I wish you could wake me up in the morning", with Simon Cowell jokingly deeming her comment "awkward".
The clip follows a long line of promotional clips for the show's second season.
It was recently reported that Nick Jonas would be joining Demi Lovato at the X Factor USA Judges' Houses stage, while Justin Bieber is rumoured to be helping LA Reid.
The X Factor USA returns with a two-night premiere on Wednesday, September 12 and Thursday, September 13 on Fox.