The singer, who was eliminated by mentor LA Reid on the first live episode, will join Taryn Southern in co-hosting tonight's episode of the live pre-show, filling in for Dan Levy.
Lomax told the official website: "It's going to be a new venture for me but I'm very excited about it. I'm totally excited to see all of my friends. I've missed them a lot.
Lomax continued: "It's a pretty intense change from performing all the time in rehearsals with a lot of attention to not doing that anymore. But getting back and reconnecting with people... it's going to be fantastic!"
He added: "I bring a lot of energy to every situation and hopefully I'll be able to give my own take on different questions and get along with whomever I'm interviewing."
Viewers can watch the X Factor online live pre-show from 7/6c here.
Lomax previously said that while he is "disappointed" by his early exit from The X Factor, he is looking at the situation in a "positive light".
"I have to... realise that I've accomplished what not many people have," he told MTV News following his departure.
"I think [LA] is an outstanding guy. I wish that he made a different decision, obviously, but he could only take three, and those three guys are outstanding as well. It's a shame he didn't pick me."
> Simon Cowell: 'Initial X Factor rejection good for Melanie Amaro'
> Paula Abdul: 'InTENsity will continue to make music'
The X Factor's Top 11 will return to the stage tonight for their third round of live performances, with another act facing elimination on tomorrow night's live results show.
Lomax, Tiah Tolliver, Simone Battle, the Brewer Boys and Dexter Haygood were the first finalists to be eliminated this season in a twist that saw each judge having to vote off one of their own acts (or in Simon Cowell's case, two acts).
Paula Abdul's group inTENsity were the first casualty of the public vote when they were sent home last week after falling into the bottom two alongside Stereo Hogzz.
The X Factor airs tonight at 8/7c on Fox
Watch Phillip Lomax performing on The X Factor below: