Louis was spotted taking a seat next to his boss and current X Factor judge Simon Cowell on the judging panel, while Simon watched his acts rehearse on stage.
'Story of My Life' singer Louis was later pictured hanging out backstage with this year's hopeful Jay James Picton.
Former Navy soldier Jay looked rather chuffed as he grabbed a quick photo with Louis. Commenting on the snap, Jay simply tweeted: "Top lad!"
For Louis, X Factor is a familiar place. Louis, along with bandmates Niall Horan, Zayn Malik, Liam Payne and Harry Styles, auditioned as solo singers for the seventh series of the talent show in 2010.
They failed to progress through to the Judges' Houses stage of the competition, but were soon put together to form a five-piece boy band.
Making it through to the live shows, 1D finished in third place, and were soon propelled to international success.
As their global record-breaking success shows, they are now regarded as one of the most successful boy bands ever!
Seeing as Louis' bandmate Niall popped down to the X Factor studios last week, will Harry, Zayn and Liam be paying a visit themselves anytime soon?!
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