The 22-year-old Pretty Little Liars actress hit the carpet with BFF Izak Rappaport, sister Shaylene and co-star Shay Mitchell.
“Cannot wait for everyone to see what me and @IzakR are going as tonight :))” Ashley teased on Twitter of her costume for the celebration.
Shay, 25, channeled Beyonce for her costume.
TELL JJJ: Whose costume do you like the best?
30+ pics inside…