The now global sensation, One Direction, which composed of Tomlinson, Niall Horan, Liam Payne, Harry Styles, and previously, Zayn Malik, was formed and finished third in the seventh series of the "The X Factor" in 2010.
The group signed with music mogul Simon Cowell's record label Syco Records.
Tomlinson, 23, will join Cowell at the judges' houses stage of the singing competition series. He will help the music mogul choose the contestants from his Overs category to be taken to the live shows, reported Entertainment Weekly.
Trainor will help Rita Ora narrow down the contestants in Girls category, Ronson will assist Nick Grimshaw in choosing the Boys, and Glynne will help Cheryl Fernandez-Versini (formerly known as Cheryl Cole) select the groups.
The judges' houses segment will be broadcast the last weekend of October.
There were plans to live broadcast the segment from the judges' houses, but due to "logistical and technical reasons" the plans have been scrapped.