Winner James Arthur and runner-up Jahmene Douglas joined fellow stars Ella Henderson, Rylan Clark, Christopher Maloney, Union J and District 3 at the Odyssey Arena on Wednesday night.
And they received a warm welcome from the crowd as they took to the stage - where they'll also end the 2013 tour in style on Thursday night.
"Belfast, you were sick!!" James Arthur declared after the show.
"Loved the show tonight!! Thank you, Belfast!" Ella tweeted, adding plenty of kisses.
"Great crowd in Belfast tonight!!!!" Rylan added, while Christopher also thanked fans in the city for "such a great night".
But they all admitted it was emotional to see the tour coming to an end.
Jahmene, who celebrated his birthday on stage at the O2 in Dublin when District 3 led the audience in singing Happy Birthday to him, also found time to tweet a picture of Ella "coming under attack".
The young singer was going through her sound checks ahead of the show when she was joined for a dance by the mascots of resident ice hockey team the Belfast Giants.
The X Factor Live Tour has been one of the biggest selling arena tours in the UK for the last eight years, with more than two million people seeing the live show.