According to People magazine, actresses America Ferrera, Debra Messing and Star Jones will also be joining them at the Democratic Party's convention in Philadelphia next week, where Hillary Clinton will be accepting the nomination to run for President this November.
In an Instagram post 19-year-old Moretz made the announcement.
"I am so happy to announce I will be speaking at the democratic national convention! #DNC #ImWithHer going to be such a beautiful historic day and I can't believe I have the immense honor of being part of it. Thank you @hillaryclinton!"
"The honor! The thrill! We promise not to copy off Michelle Obama's homework, dreamy as she is ?? #imwithher.