Season 12 Semifinals

The Semifinals of Season 12 of America's Got Talent aired from September 5, 2017 to September 13, 2017. A total of 22 acts performed. 10 acts proceeded to the Finals, and 12 acts were eliminated.
 * Italics indicate that the act was either chosen to move on or eliminated in the Judges' Choice, which means they finished in either 5th or 6th in America's Vote.

Process
From the 22 Semifinalists, 11 acts performed each week over two weeks. Each week, 5 acts moved onto the Finals.

The contestants that came in fourth, fifth, and sixth place in America's Vote fight for votes online in the Dunkin' Save. The act who received the most votes earned a spot in the Finals. The judges voted between the two remaining acts for the last spot of the week in the Finals.

Week 1
Main articles: Episode 1217 and Episode 1218

Performing (12/11)
 * Billy & Emily England, Extreme Rollerblade Duo
 * Chase Goehring, Singer/Guitarist
 * DaNell Daymon & Greater Works, Gospel Choir
 * Darci Lynne, Singing Ventriloquist
 * Eric Jones, Magician
 * Evie Clair, Singer/Pianist
 * Johnny Manuel, Singer
 * Mike Yung, Singer
 * Preacher Lawson, Stand-up Comedian
 * Sara and Hero, Dog Act
 * Yoli Mayor, Singer

Week 2
Main articles: Episode 1219 and Episode 1220

Performing: (9/11)
 * Angelica Hale, Singer
 * Mandy Harvey, Singer/Ukelelist
 * Merrick Hanna, Dancer

Upcoming acts

 * Celine Tam, Singer
 * Christian Guardino, Singer
 * Colin Cloud, Mentalist
 * Diavolo, Acrobatic Dance Group
 * In The Stairwell, A Cappella Group
 * Kechi, Singer
 * Light Balance, Light-Up Dance Crew

Trivia

 * During the third quarterfinal results show, it was revealed that Merrick Hanna would perform in Week 1, but for unknown reasons, he ended up performing in Week 2.
 * Chase Goehring, DaNell Daymon & Greater Works, and Mike Yung were all not announced for Week 1 but have confirmed on their own social media that they are performing on Tuesday. This means that more than one act had to be moved from their Week 1 slot
 * During the third quarterfinal results show, it was revealed that Mandy Harvey would perform in Week 1, but for unknown reasons, she ended up performing in Week 2.