Ed Sheeran and Little Mix are also among the artists who will take the stage during the programmes from next week as the competition hots up.
Will's BBC1 show and BGT used to go head to head for Saturday night viewers although The Voice was moved earlier in the year for its recent third run.
Former X Factor contestant Ella Henderson and The Vamps are also slated to perform.
Henderson will be singing her track Ghost on Monday, Sheeran will perform Sing on Tuesday, The Vamps will be on stage on Wednesday with Last Night and Will is to showcase new track Birthday on Thursday.
The 2013 BGT winner Attraction and finalists Richard And Adam will feature in the last of the semi-finals a week on Saturday.
Viewers can see X Factor winners Little Mix join forces with dance group Diversity for a performance of the girl group's hit Salute during the final on June 7.
A total of 45 acts are left in the competition and for each semi-final the act with the most votes will go straight through to the climactic show with judges Simon Cowell, Amanda Holden, Alesha Dixon and David Walliams choosing one of the two runners-up each night to join them.