The 21-year-old singer was a guest judge during the audition stage of this year's competition before Nicole Scherzinger was appointed as the permanent judge.
The 'Hot Right Now' singer performed her new single 'Shine Ya Light' on The X Factor tonight (November 4).
Following her performance, presenter Dermot O'Leary revealed that Ora was present when acts including Rylan Clark and Kye Sones were discovered.
O'Leary then asked Ora who she enjoyed watching the most in the competition.
She replied: "I have to tell you the truth, I love watching James Arthur perform."
Boyband One Direction had also previously revealed that Arthur was their favourite act in the competition.
Photo gallery - The X Factor number ones week results:
Copyright: Ken McKay/Thames/Rex Features