Burlesque performer Beatrix Von Bourbon and 9-year-old singer Malaki Paul are among the list of acts who will appear during Wednesday's (May 9) live show.
Stand-up comedian Gatis Kandis, girl group Be Minor and singer/dancer Chica Latina will also perform.
The line-up is completed by 40-year-old ballroom dancers the Sugar Dandies, singer Sam Kelly, magicians Brynolf and Ljung and dance group Nu Sxool.
Ashleigh & Pudsey, Jonathan and Charlotte and Only Boys Aloud are among the acts that will perform during Saturday's live final.
The Britain's Got Talent semi-finals continue tomorrow (May 9) at 7.30pm on ITV1.
Photo gallery: Britain's Got Talent's third semi-final: