Dermot O'Leary hosts the fifth live show of the series. This week, the eight remaining acts meet Mariah Carey and must perform her songs for the judges and the viewers. The viewers will then vote for their favourite and the two acts with the lowest number of votes will sing again for the judges who will choose to save one act and send the other home.
| Name | Type | Role | |
|---|---|---|---|
| Diana Vickers | Guest Star | ||
| Mariah Carey | Guest Star |