The nineteenth episode of Season 12, and the two hundred and eighty-fourth episode of America's Got Talent overall, aired on September 12, 2017. It was the second of two Semifinals performance episodes and took place in the Dolby Theatre. 11 acts performed for 5 spots in the Finals.
Despite being eliminated in the Quarterfinals, The Pompeyo Family returned to the competition.
|1. Celine Tam||Singer|
|2. Colin Cloud||Mentalist|
|3. Christian Guardino||Singer|
|4. In The Stairwell||A Capella Group|
|5. Merrick Hanna||Dancer|
|6. Mandy Harvey||Singer|
|7. The Pompeyo Family||Dog Act|
|8. Diavolo||Acrobatic Dance Group|
|10. Light Balance||Light-Up Dance Crew|
|11. Angelica Hale||Singer|
- This episode was delayed 1 hour later than the normal start time due to the "Hand in Hand: A Benefit for Hurricane Relief" telethon.
- This is the first Semifinal in which every act received at least one standing ovation.