Olly will be one of five guest stars for the second stage of the singing competition, airing next Saturday (February 4) on BBC One.
Having started earlier this month, Let It Shine will follow the hunt for talented singers to star in a new musical based on the songs of Take That.
The second stage of the competition will see the talented contestants perform together in five group numbers for the very first time. In all-singing and all-dancing extravaganzas, they will seek to prove their worth as they collaborate with some of the UK’s most-loved artists with spectacular staging and one big song after another.
The guest performers revealed today are Busted, Beverley Knight, Melanie C, Olly Murs and Kaiser Chiefs.
Five groups of eight individuals will perform with one of the guest artists. The judges will then select five individuals from each group to go through to the live finals next year.
Lulu was previously announced to join permanent judges Gary Barlow, Dannii Minogue and Martin Kemp as guest judge for this second stage of the competition.
Guy Freeman, Editor, Let It Shine says: “Having seen everyone perform as individuals in the auditions, this spectacular show is all about them working together in groups - supporting each other and their guest star artist.
"Singing and dancing, these specially arranged and staged performances will definitely put them through their paces, as well as provide viewers with some show-stopping entertainment.
"The contestants have really been putting the work in and I'm sure the judges are going to have some tough decisions to make.
"Those who make it through this stage will be one step closer to the once-in-a-lifetime opportunity of performing in a new touring musical featuring the songs of Take That.”
Let It Shine is hosted by Graham Norton and Mel Giedroyc and airs on BBC One on Saturday nights.