X Factor Judges Houses 2015: Louis Tomlinson amongst guest judges
Meghan Trainor, Jess Glynne and Mark Ronson will also appear on the show
The four stars who will be helping the X Factor judges at Judges' Houses have been revealed.
One Direction star Louis Tomlinson (23) will take time out to aid Simon Cowell (55) in whittling down his Over 25s category.
Meanwhile Cheryl Fernandez Versini (32) will be joined by singer Jess Glynne (25) to judge the Groups and Rita Ora (24) will avail of the advice of All About That Bass singer Meghan Trainor (21) for the Girls.
Superstar DJ and producer Mark Ronson (40) will be helping BBC Radio 1 presenter Nick Grimshaw (31) through his first, undoubtedly difficult, judges' houses stage with his Boys. They may eve have a quiff-off.
Given he's still presenting the breakfast show Grimmy will host his category's auditions in Manchester.
It is rumoured Rita Ora will head to LA for hers.
It had been suggested that Louis Walsh would return to help Simon out at Judges' Houses and it's still a possibility he will return in some way.