The new show launches next Monday, December 9, on ITV.
Nicole Scherzinger and Simon Cowell will appear as permanent judges, joined by various industry experts, according to The Sun newspaper.
The tabloid reports that Louis, who appeared on The X Factor: Celebrity, had been offered the role of an adviser but declined.
"Louis had a fantastic time on X Factor: Celebrity and was confident he would be back for The Band," a source explained. “He obviously has a lot of experience working with bands such as Westlife.
“But Simon had other ideas. He felt it would make more sense to have him mentoring the boys and Nicole looking after the girls. Louis was offered a role as an adviser.
“But it soon became clear there was no real job, so he turned the offer down.”
A source insisted that while Louis would not be a part of the show there was "no bad blood or fallout".
They said: “Louis respects the producers’ decision and knows they do what is best for the show. There is certainly no bad blood or fallout.”
Dermot O'Leary will return to host the series with Nicole and Simon.
The X Factor: The Band will air over four shows across one week in December.
The series will begin on Monday, December 9 at 8:30PM on ITV.
There will then be further episodes in the week on Wednesday, December 11 and Friday, December 13 also at 8:30PM. All episodes run for 90 minutes.
A fourth and live final episode will air on Sunday, December 15 at 8PM.
The X Factor: The Band replaces an originally planned All Stars series.